Attorneys who filed class actions against Target Corp. over its security breach last month have moved to coordinate the swelling tide of litigation, estimated at nearly 50 lawsuits.

Target on Dec. 19 announced a breach in security involving debit and credit card transactions at its stores across the country. The breach potentially affected 40 million customers who made purchases between Nov. 27 and Dec. 15—the peak of the holiday shopping season. Target has said it was in touch with state attorneys general, the U.S. Secret Service and the Department of Justice in investigating what happened.