I have a grandfathered AT&T Unlimited plan and rarely go over 5GB. I received a message when I got close last month. I went over on the last day of my billing cycle. I'm at 5.2GB for this month and haven't received a message. I didn't hear from them most of the other times that I've gone over. I'm going to check my when I'm not home tomorrow to see if it's being throttled. Is it common to only receive a warning from them once in awhile?