The Supreme Court told T-Mobile USA that clauses in its contracts designed to prevent customers from taking class actions were not legal. The clauses were part of three cases involving the legal remedies available in millions of cell phone contracts.

T-Mobile bans class actions in a part of its contracts and orders consumers to resolve any complaints through arbitration.  Its lawyers claimed that federal law, which generally requires that arbitration clauses be enforced, overrules those state laws that limit the ability of companies to ban class actions.

Consumer groups say class action bans are unfair, because in legal disputes over small amounts of money, individuals may not have the incentive to file suits.

However, the Supreme Court has decided that class actions can be decided by a judge and that T-Mobile' s class action clauses do not hold any legal power at all.