Why You Shouldn't Bring Your Phone to a Protest in the US
How to protect yourself from digital surveillance at protests.
Dear friends,
A couple of weeks ago, in my series of posts about protesting safely, I wrote this:
Your smartphone is a tracking device
If possible, leave your smartphone behind and take a burner phone—one with prepaid minutes that can call or text, maybe with a map, but nothing more. Don't save any names or numbers to it—if it gets lost, it needs to reveal nothing about your habits, location, or contacts.
Some folks thought I was being melodramatic, shrugged their shoulders, and packed their phones without a second thought. After all, our phones are how we stay safe, connected, and informed, right? They’re how we record and share the events of the day!
But again I’d like to caution you that in the context of a protest, that same device can quietly become a surveillance tool, revealing more about you than you ever intended to share.
I’m not being dramatic— this isn’t theoretical. It’s already happened in the US, to peaceful demonstrators. Here’s how it works.
Stingrays: Surveillance Without a Warrant
‘Stingrays’— also known as ‘IMSI catchers’ and ‘Cell Site Simulators’— are surveillance devices that pretend to be legitimate mobile phone towers.
Here’s the simplest way to think of it: when your phone is on and has signal (even just for emergency calls), it's constantly sending out little pings looking for the nearest tower. The simulator intercepts those pings and tricks the phone into believing it's connecting to the strongest available signal, even though it’s not. When your phone is nearby, it almost always automatically connects, thinking it's connecting with your usual cell network.
Once connected, the stingray can:
Collect the IMSI (International Mobile Subscriber Identity), which uniquely identifies your SIM card
Log metadata like your location, who you’re calling or texting, and when
And in some cases, intercept the content of calls or messages (though this is trickier with newer encryption standards.)
This information can be used to locate you, identify you, and link you to others in the area.
The technology was originally developed for counter-terrorism and military use. But over the past decade, it’s quietly been handed down to local and federal law enforcement agencies. It’s often deployed at large gatherings, including protests, without the public being notified—and frequently without a warrant.
During the 2015 protests in Baltimore after the police killing of Freddie Gray, stingrays were used to locate and track protest organisers in real time1. Internal records later showed that police didn’t just use them for emergency situations—they used them routinely, often without court approval2.
In New York, the NYPD has used stingrays over 1,000 times3—almost always in secret4. From Occupy Wall Street to Black Lives Matter, there’s strong evidence that these tools were deployed to collect data from entire protest crowds, sweeping up phones indiscriminately56
And in Miami in 2020, it was only after journalists filed public records requests that officials admitted to using a stingray during the George Floyd protests. No warrants had been issued7.
These devices don’t discriminate. If your phone is switched on and nearby, it will likely be captured.
Encryption Won't Save You
When your phone connects to a real mobile network, your conversations, texts, and some data are typically encrypted—scrambled in such a way that only your phone and the network can understand them. This is meant to protect your privacy. But here’s where cell site simulators get clever.
Most stingrays don’t bother breaking encryption (or at least not at first). Instead, they exploit a trust loophole.
When your phone connects, the simulator can either:
Pretend to be an older, less secure network (like 2G, which often doesn’t enforce encryption at all).
Tell your phone to disable encryption entirely, which some devices will do without complaint.
Or simply collect metadata, which isn’t always encrypted anyway—things like your device ID, location, or who you're contacting.
More advanced simulators (especially those used by state-level actors) might actually decrypt communications, but this depends on the phone, the encryption method, and how much time or computing power the operator has. Some encryption, like that used in end-to-end encrypted apps (Signal, WhatsApp, etc.), remains secure even if your phone is on a fake cell tower, because the encryption happens before the data hits the mobile network.
In short: encryption helps, but it likely won’t save you. Stingrays are designed to work around it, especially when they can downgrade the connection to a weaker standard. If your phone still says '4G' or '5G' while connected to a stingray, encryption might still be active—but if it suddenly drops to '2G' that’s a red flag.
Metadata: The Invisible Paper Trail
Even if you aren’t posting, filming, or texting during a protest, your phone still sends signals. Every signal it sends and receives carries metadata—a layer of information that records the who, where, and when of your activity. That includes which towers your phone connected to, which apps pinged servers, and whether your Bluetooth, Wi-Fi, or GPS was active.
It might seem like harmless technical detail. It isn’t.
Metadata can be used to reconstruct your movements, determine who you stood near, when you arrived, when you left, and how long you stayed. It builds a pattern of behaviour—one that can be cross-referenced with other people’s data to create maps of associations and networks. And it’s been used by law enforcement agencies to track protestors back to their homes, workplaces, or other locations to identify them.
In 2020, during the nationwide protests following the murder of George Floyd, federal agencies including the Department of Homeland Security and the FBI accessed geolocation data from mobile devices to monitor protest movements.8 In some cases, they purchased this data from private brokers—legally bypassing the need for a warrant91011.
That same year, police departments began using geofence warrants—a request to Google or Apple for data on all devices in a given area at a given time. In Minneapolis, Google handed over location history for everyone near a looted store, regardless of whether they were involved. Peaceful protesters, passersby, journalists—all swept up in the same dragnet.12
During the 2020 protests in Kenosha, Wisconsin, following the police shooting of Jacob Blake, multiple geofence warrants were issued to Google. These warrants sought information on devices present in areas near protests, including public parks and businesses, again potentially capturing data from peaceful protesters and bystanders.13
In each of these cases, metadata—not content—was the key to surveillance. And once collected, that data doesn’t go away. It can be stored, analysed, and revisited later.
How to Protect Yourself (Ranked by Risk)
My point is: you don’t need to be doing anything wrong to be swept up in a dragnet. So if you choose to protest, you need to think like someone who might be targeted, because in a data-driven system, your presence is enough.
The safest phone is no phone. But that’s not always realistic. Some people need a way to stay in touch, check directions, or call for help in an emergency. The question becomes: how much risk are you willing to accept?
Let’s walk through your options, from the strongest protection to the most compromised.
1. Leave It At Home and Use a Burner
This is still the gold standard. A basic prepaid phone with no smart features offers the best protection against surveillance. No apps. No accounts. No saved contacts. No wireless data. Just texts and calls in case you need them.
Best practice: Buy it in cash, activate it away from home, and never log in to any personal accounts. Memorise contact numbers, and only ever use it only for urgent communication. Keep it switched off unless needed.
Risks and limitations: You’ll lose access to maps, group chats, and media capture (though you can always take a paper map and a pocket (disposable/ film) camera). If it’s seized, it could still show who you’ve texted or called. And if it’s turned on near a stingray, it’s still traceable—just harder to tie back to you.
This is your safest option if you don’t need smart features and can plan everything in advance. And there’s no reason not to do that: I’ve laid it all out here.
2. Use a Faraday Pouch
A Faraday pouch blocks all signals—Wi-Fi, cellular, Bluetooth, GPS—by enclosing your phone in a conductive shield. As long as your phone is inside the pouch, it’s effectively invisible to towers, stingrays, and app tracking.
Best practice: Buy one that fully seals (some don’t). Put your phone inside and test it before you leave—try calling it or pinging it from another device. You want silence.
Risks and limitations: It’s easy to forget the need for security and take your phone out to check a message or take a photo, exposing it mid-protest. If you’re detained and your phone seized, they may try to force the phone open or access cloud backups. And without your phone accessible, you lose emergency comms, navigation, and coordination tools. It also attracts attention if authorities are looking for ‘non-compliant’ devices.
A Faraday pouch is a good compromise if you need to carry your phone but want it shielded most of the time.
3. Keep it Switched Off
If you must take your regular phone, lock it down as tightly as possible.
From my post “How to Protest Safely in Trump’s America”:
If you have no alternative but to bring it, back it up, then strip it down: delete personal photos, documents, saved passwords, anything sensitive. Log out of Google, Apple, and Meta services completely—these companies have handed over user data before, and in this climate, they’re likely to do it again. Switch it off near home, and unless there’s an emergency, keep it switched off. Prior to and after the event, use encrypted messaging (Signal) to communicate about it, ensuring disappearing messages is switched on. Treat your digital footprint like it's radioactive.
Before you leave home, turn off location tracking. Disable biometric unlock (face and fingerprint) as it can be more readily forced. Use a strong passcode. Switch off Bluetooth, cloud sync, and automatic backups. Anything connected can be accessed—by companies or the state. And then make yourself secure by turning it off, and only turning it back on when the event is over and you’re at least a couple of miles from the site (and a lot further if you don’t live within walking distance).
If you live close to the protest and are arriving on foot, power it down at least two miles from the site. If you live further away—say, you’re travelling in from another part of the city or a neighbouring town—keep it off the entire time you're away. Only turn it back on when you’re safely home and behind your own front door.
Why so strict? Because mobile signals don’t just show where you were. They show how far you travelled to be there. In a climate where protestors are being targeted, you don’t want to have to explain why your device shows you were miles from home near a protest zone. That alone can raise flags.
Let’s break down the usual justifications for not switching it off:
“I need it for navigation.” Use a paper map. Plan your route in advance. Navigation apps are not worth the risk.
“What if there’s an emergency?” Carry a burner phone that’s switched off unless needed.
“I need to coordinate with others.” That’s what burners are for. Cheap prepaid phones can send texts and make calls—just enough for coordination, without the exposure risk of a smartphone.
“I need the camera to document!” Use a disposable/ film camera- it doesn’t have a digital backdoor.
Risks and limitations: The moment you switch your phone on, Stingrays can grab your device’s identifiers. Apps that weren’t fully closed might send data in the background. And if your phone is confiscated, even the best protections can fail if it’s unlocked or your backups aren’t secure.
Yes, carrying your regular phone—stripped down and powered off—is the lowest-cost option if you can’t afford a burner. But it’s also the riskiest, and requires discipline and forethought. Use it only if you understand the trade-offs and are prepared to react quickly.
Know The Risks and Make a Plan
In 2025, showing up to protest in the United States means stepping into a heavily surveilled environment. Bringing your phone — even if you never touch it— means being potentially traceable, identifiable, and linkable to others in the crowd. It means that you could be added to databases, flagged for future monitoring, or implicated by association.
That doesn’t mean you shouldn’t go. It means you need to prepare like your presence could be scrutinised—because it can be.It’s not about guilt. It’s about exposure.
You may be attending a peaceful demonstration in good faith. But the systems being used against protest movements today aren’t interested in why you were there. Your phone can place you at the scene, map your movements, and reveal who stood beside you. That information may later be used in investigations that have little to do with protest rightsand everything to do with political repression.
So if you’re going out to protest, think carefully, and make informed choices. Prepare yourself before the day, and don’t let convenience make the decision for you. Your phone can serve you, or it can expose you. It all depends on how you carry it, when you use it, and what you’ve done to protect it ahead of time.
Thank you for showing-up for democracy.
—Lori
International Center for Not-for-Profit Law (ICNL). Protesting in an Age of Government Surveillance: Legal Reforms to Protect Demonstrators. US Program Briefer. Available at: https://www.icnl.org/resources/research/us-program/protesting-in-an-age-of-government-surveillance [Accessed 14 Apr. 2025].
ACLU News & Commentary. (2015). Maryland Court Considering Key Question on Legality of Stingray Use. [online] Available at: https://www.aclu.org/news/privacy-technology/maryland-court-considering-key-question-legality [Accessed 14 Apr. 2025].
New York Civil Liberties Union (NYCLU). (2016). NYPD Has Used Stingrays More Than 1,000 Times Since 2008. [online] Available at: https://www.nyclu.org/press-release/nypd-has-used-stingrays-more-1000-times-2008 [Accessed 14 Apr. 2025].
The Guardian. (2016). NYPD tracked citizens’ cellphones 1,000 times since 2008 without warrants. [online] Available at: https://www.theguardian.com/us-news/2016/feb/11/new-york-city-police-tracked-cellphones-without-warrants-stingrays [Accessed 14 Apr. 2025].
VICE. (2017). The NYPD Sent Video Teams to Hundreds of Black Lives Matter and Occupy Protests. [online] Available at: https://www.vice.com/en/article/the-nypd-sent-video-teams-to-hundreds-of-black-lives-matter-and-occupy-protests/ [Accessed 14 Apr. 2025].
Brennan Center for Justice. (2017). New York City Police Department Surveillance Technology. [online] Available at: https://www.brennancenter.org/our-work/research-reports/new-york-city-police-department-surveillance-technology [Accessed 14 Apr. 2025].
American Civil Liberties Union (ACLU). (2014). ACLU-Obtained Documents Reveal Breadth of Secretive Stingray Use in Florida. [online] Available at: https://www.aclu.org/news/national-security/aclu-obtained-documents-reveal-breadth-secretive-stingray-use-florida [Accessed 14 Apr. 2025].
International Center for Not-for-Profit Law (ICNL). (2023). Protesting in an Age of Government Surveillance: Legal Reforms to Protect Demonstrators. [online] Available at: https://www.icnl.org/wp-content/uploads/2023.02-US-Program-Briefer-Protest-Surveillance.pdf [Accessed 14 Apr. 2025].
Brennan Center for Justice. (2024). Closing the Data Broker Loophole. [online] Available at: https://www.brennancenter.org/our-work/research-reports/closing-data-broker-loophole [Accessed 14 Apr. 2025].
Project On Government Oversight (POGO). (2022). Police Quietly Obtain Private Location Data with a Checkbook and not a Warrant. [online] Available at: https://www.pogo.org/analysis/police-quietly-obtain-private-location-data-with-a-checkbook-and-not-a-warrant [Accessed 14 Apr. 2025].
The Wall Street Journal. (2024). U.S. Spy Agencies Know Your Secrets. They Bought Them. [online] Available at: https://www.wsj.com/politics/national-security/u-s-spy-agencies-know-our-secrets-they-bought-them-791e243f [Accessed 14 Apr. 2025].
Whittaker, Z. (2021). Minneapolis police tapped Google to identify George Floyd protesters. TechCrunch. Available at: https://techcrunch.com/2021/02/06/minneapolis-protests-geofence-warrant/ [Accessed 14 Apr. 2025].
ACLU of Wisconsin. (2022). Technology Surveillance of Protesters. Available at: https://www.aclu-wi.org/sites/default/files/wysiwyg/technology_surveillance_of_protesters_4_14_22_2.pdf [Accessed 14 Apr. 2025].
Thank you Lori-I read your last article on this topic and didn’t really give it the importance required until now. I’ll take your advice-getting a no frills burner phone for emergency use only with local protests and I appreciate you’re spelling it out in layman’s speak and offering clear & concise guidelines and multiple choices. Thanks for ensuring our privacy and safety!
Wow! This is an extremely thorough and well organized post, which should help protect protestors, journalists and casual bystanders in the increasingly fraught struggle between oppressive governments and resistors today.
It’s probably worth mentioning that Apple can no longer offer ADP (Advanced Data Protection) in the UK to new users, reducing the level of protection available on its devices. And who knows what incursions the Trump regime will make into our digital privacy in the coming weeks and months.
We all need to be very careful going forward.