Just to add another data point - during a recent move, I was temporarily using iPhone + MyWi as my primary internet connection. Nothing particularly egregious

Just to add another data point - during a recent move, I was temporarily using iPhone + MyWi as my primary internet connection. Nothing particularly egregious - just basic web browsing and SFTP. This lasted for about a week. That was at least 1 billing cycle ago, and I've yet to hear a peep from AT&T. My suspicion is AT&T is (currently) just looking for users with excessive data usage.