I agree to a certain extent, yeah it does get erased when flashed, take my look at it though:
My phone gets nicked at work, (no-one I work with knows how to flash a phone, they can barely change ringtones, I do all the work on most of their phones when they are stuck) their going to turn it off straight away but they will try it when they get home, as soon as they put their card in (phones not locked purposely) it sends a text to my wifes phone complete with co-ordinates, I can soon look this up on Google maps and see where my phone is, not hard to work out which person nicked it
Plus I can send various commands to the phone without them knowing