AT&T has lost an attempt to block a class-action lawsuit which is suing the carrier for alleged over-charging roaming fees. AT&T, known at the time as Cingular Wireless had tried to argue before Washington State's Supreme Court that the customers had signed a contract which included a clause forbidden the customer from starting a class-action lawsuit, but the court decided that the clause was unfair and sent the case back to the trial court in King County where it began.

The lawsuit was filed back in 2004 against Cingular has claimed that the carrier advertised free roaming in areas covered by AT&T Wireless - which at the time was actually a separate company - but charged customers for the roaming service. It is claimed that Cingular had overcharged customers between $1 and $40 per month.

Public Justice, America's public interest law firm, based in Washington, DC which represented the customers, argued that Cingular's class action ban is "unconscionable" under state law because it forces customers to arbitrate their individually-small claims one-by-one and denies them the option of acting as a group with a common grievance for any reason. Public Justice also argued that federal law does not trump state laws that preclude companies from barring class actions in contract provisions.

"This decision is likely to have a significant influence on the way other courts think about this issue," said Paul Bland of Public Justice, who argued the appeal. "A number of courts around the country are wrestling with this issue right now, and the Washington Supreme Court's opinion is so thoughtful and well-reasoned that it is likely to persuade many other courts to also protect consumer rights."

In striking down the class action ban, the court emphasized that, if Cingular's customers couldn't bring a class action, they would be prevented from pursuing valid claims against the company. Writing for the 6-3 majority, Justice Tom Chambers stated that, if enforced, Cingular's class action ban would "effectively den[y] large numbers of consumers the protection of Washington's Consumer Protection Act."

The court also recognized that class actions are necessary to "strongly deter future similar wrongful conduct, which benefits the community as a whole."