... to sell Bitcointalk, Reddit and social media accounts were probably hacked or compromised accounts and asking Ethereum as payment.
Well, with
my experience in the field, I believe all the accounts he sold were hacked and stolen accounts. Most accounts are inactive for a long time, although he mentioned they had some activity, i believe it was used by him to join the bounty campaign.
Another case might, I presume there's no real accounts to be sold and might trying to scam users and those will take a risk would fall on this scammer's trap.
It is also the case, but the rate is lower. If he just wants to scam, he can create a new account and post, but he used a Full member account. Wouldn't it be a waste to vandalize an account just because of uncertainty scam, right?