Have you heard of AT&T reacting negatively, so far, in any case of unauthorized iPhone tethering?

I’ve been advising people that if you tether you should do two things:
1) stick with light usage (to be a good neighbor, and to avoid rubbing it in AT&T’s face by creating any measurable strain on the network in your immediate area); and
2) understand you’re doing it at your own risk (because it violates the TOS).

But I was recently challenged to come up with any example of actual “risk” so far. I haven’t googled it much, but I’m reaching out to see if you’ve noticed anything.

I think AT&T might start more actively trying to prevent unauthorized tethering once they start offering tethering as a paid option (although it’s not clear how they would do this across the board, given the various tethering solutions people have). What do you think?