Yes if he has indeed private keys, then he could get the bitcoin for hisself, that would make sense, but selling them don't make sense so this is a pure scam attempt. I think he need to be IP banned.
And ban all Change**Bags Usernames created today. He is/was constantly switching them.
There is a bot i think from Mitchell which do a job.
This detect new created users and report them as far as i know.
I don't know why people wants to spam a lot, really low to zero chances to scam others.