A huge number of firms treat the SSN as "private" and having knowledge of an SSN proves that you are that person. It's not what they were designed for, but good luck explaining that to the electric company and the gas company and the credit card company and the bank...
"What can you do?" With Duke Energy, the electric provider in my last apartment complex, you would have absolutely no problem registering for electric in someone else's name and having them on the hook for it if you knew their SSN.
"What can you do?" With Duke Energy, the electric provider in my last apartment complex, you would have absolutely no problem registering for electric in someone else's name and having them on the hook for it if you knew their SSN.