I have a 2gb data plan on my 3GS (had to drop the unlimited from my 2g). I tether all the time, but I haven't since I heard about AT&T cracking down on it. I use MyWi to tether. If I keep my tethering under 1GB, will they catch me?
I use it sometimes, and I've never been caught. However, I plan on always using a VPN in the future to completely eliminate any chance of AT&T catching me. I only use tethering if I'm doing homework or something else that is vital in a place that has no useable wifi connection, so I'm not going to pay those vampires at AT&T more just fore that.
I don't think they will, but they could look at the packets and tell if you are tethering or not.
If you establish a VPN connection, they will not be able to know, as the data will be encrypted. It will be hard for them to prove anything.
You can either pay a few bucks a month to a company that sells VPN access or create one on your home router. I like having a British IP that allows me to watch video on BBC's iPlayer and Channel Four's website, so I just pay for one.How is this done?