I can see them cracking down on top users but for people using less than 5GB they shouldn't touch us. I can use more than that with just my phone. I tether rarely but I do tether if I need to.
Yeah financially it doesn't make sense for them to go after those who use it once in a blue. They can if they wanted to, and we wouldn't have a leg to stand on if they did, but I don't see them going after light tether-ers either.