Very interesting!
Super cool to see it can be used against theft.
AFAIK some apps misuse it, though. If Snapchat detects a modified phone (root for example) at any point, it might block your IMEI. (As far as the internet is concerned, they're very secretive about it) Which is a horrible decision, since a phone might be re-locked and refurbished, handed down to someone else, etc.