I got a $600 phone bill because the prison / jail system in houston texas somehow got my phone number and was able to run up over 100 calls in a 4 day period before AT&T CORRECTED THE PROMBLEM. Most all of them were made to other cell phone users. some land line owners. Oh I could call out but no one could call in. it would give a piece of a ring and then when you picked up it was nothing on the other end.