""As T-Mobile customers, each Plaintiff accepted T-Mobile’s Terms and Condition," T-Mob's response reads. "In so doing, they agreed to arbitrate on an individual basis any dispute related to T-Mobile’s services and waive their right to participate in a class action unless they timely opted out of the arbitration procedure outlined in the Ts&Cs. Neither Plaintiff elected to opt out."
Hmmm, it's this sort of clause that should be illegal. Firstly, not only for the fact that it was probably buried deep down on page 12 of their T&Cs in a four point font, but secondly for the fact that it's highly unlikely that the average T-Mobile punter has the geological amount of time available to put into a challenge - which is how long these sort of things usually take, and thirdly because they'd probably be drowned in lawyers.
T-Mobile know this, and also know that it is a scummy position to put your "highly valued" customers in. Yet they do it anyway.