AT&T to begin throttling heaviest data users on October 1 (Updated)

FTA: "[W]e’ve been told that 12,000 e-mails, 12,000 website views, 4 streaming movies and 5 hours of streaming music will start to put you close to that upper range of usage," wrote 9to5Mac.

Won't the email/web figures be mostly irrelevant in comparison to the movie/music data consumption? I wonder how much of the data capping is reaction to Netflix/Hulu consumption. I understand this is a big issue at college campuses and some businesses?