A website that runs classified ads for people it says are adult escorts and critics contend are pimps and human traffickers has won a round in a battle against Cook County Sheriff Thomas J. Dart.The 7th U.S. Circuit Court of Appeals on Monday granted Backpage.com LLC’s motion for an injunction temporarily barring Dart from pressuring credit card companies to halt their dealings with Backpage.The court directed Dart to send a copy of its order to Visa and MasterCard as well as to the U.S. Postal Service.In June, Dart …