The US system of credit reporting and associated ease of establishing credit is like super convenient. But it's largely based on trust. There isn't a whole lot of identity verification, and there are a lot of parties in the system that take identifying information at face value and run with it.

This is nice when it's actually you, but it's a giant PITA to unravel when it's not. My spouse's name and SSN was used to rent an apartment in Oakland, as well as attempts to open credit cards at the apartment address (thankfully they tried to open an account at Amex but she already had one there and they called to confirm; at least one issuer said they were likely to approve). We were able to get all the credit applications denied/cancelled, but the rental lease is harder; the leasing office says they can't do anything without a criminal complaint and Oakland PD won't talk to us.