To reiterate my point:
T-Mobile isn't the only wireless carrier that's been stretching the definition of "unlimited" data. AT&T and Verizon both reduce speeds for users who consume the most data, although Verizon only does so when its network is congested. And T-Mobile has called its tiered data plans "unlimited" since last April.
Although wireless carriers argue that a plan with throttling is still "unlimited" because users can continue to access the Internet, speed restrictions are still a type of limit placed on the user. T-Mobile is doing a good thing by offering an affordable family plan with unlimited talk and text. Why muddy it with dishonest advertising?
Here is the complete article.
http://www.pcworld.com/article/248360/tmobile_and_walmart_stretch_meaning_of_unlimited_with_cheap_family_plans.html
They might be doing something other to their "unlimited plans" as you will see
And another interesting one
https://plus.google.com/u/0/100736094401428282681/posts/Z8c2sGxq11B