Naively, I had thought this was dead.
http://www.4-traders.com/AT-T-INC-14324/news/AT-T-Tightens-Limits-On-Unlimited-Data-Plans-14158607/
http://www.4-traders.com/AT-T-INC-14324/news/AT-T-Tightens-Limits-On-Unlimited-Data-Plans-14158607/
Under a new policy, AT&T will slow download speeds for unlimited smartphone customers who in a month exceed 3 gigabytes -- roughly 5 high-definition movies -- or 5 gigabytes if they are 4G LTE users. AT&T had previously been slowing speeds, or throttling, customers who were in the top 5% of data users in their respective markets.