Obscured the credit card # but didn't think to grant the passenger some privacy and obscure their full name?
Besides, why would the NTSB hold onto the phone for years? It's not part of the aircraft, there's no real reason why they'd need to have it at all. Is it just common with US government agencies?
If I found the phone like that guy did my last thought would be to post pictures of the persons private emails and full name to the internet - and get a bunch of attention for it.