Out of all of the people Diego contacted, most didn't reply. The ones who did, sent their actual 

public key

. However, one idiot sent their 

private key

. The guy must've generated their first wallet and copied and pasted the wrong damn thing. Even though the wallet UI explicitly told you never to share or lose your private keys.

This kind of thing would've pissed Diego off in the past. But knowing his end was near, he saw some humor in it. Actually a lot. He began cracking up. This guy was fucking hopeless. Sending his private key to a stranger. And the thing was that when he checked the address it actually had quite a bit of funds in it. Not anything huge, but not anything trivial.

Anyone else with access to this private key would've probably drained the wallet. Sent it to their own. But Diego instead emailed back.

Hey, idiot. Generate a new wallet. You just sent your private key via email and now it's on someone else's database.