Shared here for public benefit.
Before going to a protest, demonstrators or observers should note that their cellphones may subject them to surveillance tactics by law enforcement. If your cellphone is on and unsecured, your location can be tracked and your unencrypted communications, such as SMS, may be intercepted. Additionally, police may retrieve your messages and the content of your phone if they take custody of your phone, or later by warrant or subpoena.
If I’m sitting on the couch, the phone is not on me. It’s on the table next to me or on a counter somewhere. I don’t even always look at it if I get a message. Sometimes I’ll wait hours after I get a message to read it.