Personally, I have done a few glitches in the past, but that is only because I feel cheated by R* due to certain bugs in the game. (e.g. the insurance glitch, cars going missing for no reason, cars that I've ordered never turning up in my garage). I never glitch an insane amount anyway, so as long as I'm only reclaiming money that was lost because of bugs in the game I feel that I'm not doing anything wrong.
There was also the whole bounty phase where people were hacking bounties and I happened to end up with around 2billion, but after a few days I think R* took that money away from most people (me included)
So what is the risk of being caught glitching? And also what happens if you are caught? I'm pretty sure people have been banned, but is that only in the case of really serious glitching?