There's also the superman problem - the burner phone would only ever appear when anonymars is missing, and vice versa, creating a real and exploitable pattern if anyone like the FBI wanted to root around in your life. All they'd have to do is query which shadow profiles match the temporal gaps correlated with your disappearance from tracking.

This is nonsense. By your logic, people go 'missing' any time they are not using a computer, whether they're reading a book, in the shower, or asleep in bed.