My last plan with AT&T I think was 10 or 15GB/month with rollover, which I had accumulated something like 30GB of data saved up over the last year.
Then one day I got a text saying I had used all my data for the month, and I thought this was quite strange.
I logged in to see the usage, and AT&T gives you an itemized bill showing data usage almost minute by minute — I think the resolution is 5 minutes intervals.
Lo and behold they claimed I used 22GB in one 5 minute interval at some random point during the afternoon that day.
I called about a half dozen times to complain and try to get it adjusted. The agents would say crazy things like, “well were you watching a video?”, or “did you download a large email attachment?”
It didn’t matter that the iPhone they said did the download showed totally normal data usage stats on the phone itself. It didn’t even matter that moving that much data in 5 minutes was technically impossible. Even when I finally got an agent to admit it must be an error and that it would be impossible to move 22GB in 5 minutes, they said they would escalate the issue and then nothing ever happened.
I never got those rollover data bytes back, and ultimately had to switch to an unlimited plan to protect from the fake overages.
So I do worry about massive theoretical maximum throughout resulting in obscene charges with no way for the customer to prove the data transfer never happened.