Alan S. Kaplinsky—who, along with partners at Ballard Spahr, submitted an amicus brief in favor of AT&T Mobility— disagreed with observers who cast the U.S. Supreme Court's AT&T Mobility LLC v. Concepcion as the end of class action litigation.

"It is important to note that this opinion doesn't mean that federal law will save an arbitration agreement that is unfair to consumers," said Mr. Kaplinsky, Chair of his firm's Consumer Financial Services Group.