What should I do with this?

[Don Pedro Dinero]

I've received this PM:

Hi Don Pedro Dinero !

I bought a full member Bitcointalk account this morning for $75. When I read his old messages, I saw that he had staked his bitcoin address to protect the account and it was you who quoted his message to save it.
I'm afraid he'll recover the account using this message...
If I give you all the proof of our transaction, can you please delete your message?

Thank you in advance !

Best regards

I've hidden his identity because buying accounts is allowed here and it doesn't seem to me a name and shame case.

[Lutpin]

First step would be verifying whether or not the user has bought the account from the actual owner.
If the owner has staked an address to protect their account, upon sale, they should have provided a signed message from said staked address proofing the sale.
Can the user not provide such a message, they might have bought the account from someone who previously hacked it, thus have no right to own that account.