Normal customers shouldn't be worried. I imagine the only customers getting letters are your chronic complainers, that cry about late fees because they don't pay their bills, complain because Sprint won't cover their phone for water damage, call because they think they are entitled to every discount and freebie out there and complain about coverage (probably also they same that go to town meetings to oppose new cell towers). Can't blame Sprint for wanting to purge themselves of the deadbeats.