When he was posting misleading information about my product.
To be honest , I dont see anything misleading that apart from a negative trusted account claimed to know your method and will spread if for free unless you pay him which is clearly a blackmail.
You can
use a self moderated thread to prevent this user from spamming your sales thread and apart from that I see no reason on why you would believe a words from a "possibly hacked account" because his trust rating has clearly indicates that the user cant be trusted
I think this member should be IP banned from BCT, if it is a hacked account admin can block he's IP so he don't have access.
If it is actually a hacked account then the original owner could restore it by sending a signed message to theymos. Apart from that, if no one claim that account then there is no restriction of what that person could do with a hacked account, moreover admins dont IP bann someone just because he hacked an account ( IP is pretty easy to "change" anyway )