That only usefully works if you only contact other burner phones. If you use this to talk to friends and family, it's essentially worthless as it's extremely easy to find out who the one "anonymous" contact is they keep calling, if one has the <i>network view</i> which seems to be part of the threat model here.<p>Notable example: The CIA's Sabrina De Sousa got caught in a similar way.<p>> Phone records show calls made from De Sousa’s phone to one of the kidnappers eight months before the operation and around the time of the abduction [0]<p>So: If you really want to leave no usable trace, never <i>ever</i> use the same prepaid sim card in different burner phones, rotate them every so often (<i>physically</i> destroying them after you're done) and only call and <i>be called</i> by other burners.<p>That's probably a little much, and I would advise someone trying to do this to ensure that this matches their threat model. Unfortunately that's become somewhat harder in recent years wrt to just existing in the digital space.<p>[0] <a href="https://www.washingtonpost.com/lifestyle/style/kidnapping-unravels-a-spys-career/2012/07/11/gJQAJreAeW_story.html" rel="nofollow">https://www.washingtonpost.com/lifestyle/style/kidnapping-un...</a>
I don't travel much, so the next time I do, I hope I remember to get something like this. I can't imagine doing anything that's important enough to go to jail to hide (other than it's none of their business, a separate discussion), but once customs takes it out of my sight, I don't want it back. Also, depending on the day and the agent, I may not get it back anyway.