If you are attending a protest or other high-risk event, your devices such as mobile phones might be seized by the police or private security. In case this happens, your private data becomes exposed to all kinds of risks. In regards to this consider the following:

Remote lock and erase - Android phones, in case they have the “Find My Device” option enabled, provide you with the possibility to remotely lock them with your PIN, pattern, or password or even erase all data on the phone. Google provides further instructions on how to secure seized Android devices. Similar options are provided by Apple for iOS devices such as iPhone or iPad.

Check your device - In case your device was taken from you, once you get it back make sure to check for any suspicious changes, e.g. if there are unknown apps installed or changes to settings. On Android phones, you can check whether Play Protect is turned off, as it offers protection against potentially malicious apps. In case it was turned off, make sure to turn it back on.