One day last month, when Klaus Zimmerman tried to log into his Skype account, he got an error message indicating his username and password didn't match. Concerned something was awry, Zimmerman, a computer repairman living in Wexford County, Ireland, phoned his brother and asked him to check his online status."I saw you on earlier, but your picture was gone," the brother reported. "You're now listed as living in Germany." On top of that, the person logged in was no longer answering the brother's queries.