I'm having a hard time taking the OP seriously, but it seems a large number of people leave their devices on:

mobile.nytimes.com/blogs/bits/2013/05/09/30-percent-of-passengers-accidentally-leave-a-device-on-during-flight/

The actual danger is extremely near to zero. It's likely the FAA will change their rules in due time.

So, we must ask, is the OP tattling or telling? Tattling, he's definitely tattling.

And, if I may be so bold, I would go so far as to say that having a passenger who has "reached his limit" is far more dangerous than having a cellphone left on.