How to do it:

Your security steps depend on your situation. Crossing a U.S. border (or sometimes being within proximity of one) reduce your legal protections. If you do not want to hand over an unlocked phone, consider buying a cheap travel phone. They can hold on to a phone you won’t unlock for weeks or even months. Within our borders courts have ruled police can physically force your finger onto a phone using fingerprint technology, or hold it up to your face without permission. The first thing you should do is remove biometric access and set a passcode instead.

We have reached the point where they appear to be tracking people based on protest attendance, and are demanding access at border crossings (where usual warrant rules don’t apply.) If you attend very large events like No Kings, it’s likely that volume will obscure your footprint, but if you attend protests at ICE facilities, or you are at higher-risk (such as being a legal immigrant) consider leaving your phone (and cell-enabled watch) at home.

Steps include using a safer messaging app like Signal, and learning about your phone’s security settings. Here are resources to get you started:

• Protest security for your phone: https://ssd.eff.org/module/attending-protest
• iPhone privacy: https://ssd.eff.org/module/how-to-get-to-know-iphone-privacy-and-security-settings
• Android privacy: https://ssd.eff.org/module/how-to-get-to-know-android-privacy-and-security-settings
• Guide to Signal: https://ssd.eff.org/module/how-to-use-signal
• Border crossing (varies): https://www.eff.org/issues/border-searches

Wipe your phone on command

If you anticipate being coerced into providing access to your phone at a border, and you have content or contacts you want to protect, it is possible to set up an alternative code that wipes the phone on entry. This requires extensive preparation (you need a privacy-forward operating system, not the default) and there may be legal consequences.

GrapheneOS is an alternate privacy-forward OS that allows this option.

• Here’s an Android->GrapheneOS write up.
• Here’s an iOS (Apple) -> GrapheneOS write up.