Personally I think that if your the kind of person who listens to someone who calls them "dude" and who also shows them how to use "backups" aka pirated copies then you deserve to get banned
But the fact is if your even slightly competent (which you have to be to change the firmware on your 360's drive) your going to be well aware of the consequences.
The reason you haven't seen anyone sue ms is simple. The only people using these hacks are pirates (I know I was one of them). Only a tiny minority of people are getting banned without cause if any. Not enough to cause ms any real problems.