Okay. I have some FBI agents hiding from people who want to kill them. These people are not the police, but could potentially gain access to information or resources (e.g. from phone companies) through threats. My agents currently have their mobile phones with them. I have researched (via Googling things like "how to locate cell phone" "how to trace location of cell phone" "GPS in cell phone" and some relevant posts in this comm) how using your mobile phone can reveal your location but what I'm struggling with is the level of obvious knowledge the characters would be expected to have given their jobs.
What I want to know is, would these people decide the most prudent thing to do would be to get rid of their phones as soon as possible? Or keeping them with them, but switched off? If they did keep them, would making a call be seen as "absolutely no way, completely idiotic" or "risky, but a possible course of action if our backs are to the wall?"
They're split up and would like to be able to stay in contact, but I don't want them to come across as idiots or amateurs. Initially, their pursuers don't know their phone numbers; then one of their number is captured and (as things stand at the moment) would still have his phone, with his colleagues' numbers, on him.
Any help would be greatly appreciated. I'm pretty clueless about this topic, so I'm finding it hard to make any conjecture about how my characters would view their options. Thank you in advance!