Funny comments, but jokes aside, I think we're missing a very obvious reason why he has signal. Mark most likely has contacts that are super high up in governments and coorporations who use signal since they can't trust any other app. People who say that he just tested out competition, I think you guys underestimate his technological knowledge and his resources waaay too much. If he wanted to do that he could have easily ordered someone to get him a clean phone with a sim card not linked to his name and let that device sit on his desk for testing.