I don't think anyone is able to have this amount of accounts without all of them being Newbies. And even if they are, its still very hard to believe someone created 10k accounts. Probably just a scam, and maybe that's why the thread was deleted?
Maybe not 10k accounts, but definitely a large chunk could have been compromised. It's not self-made accounts but rather accounts that haven't changed their passwords and were retrieved using the database hack (on weak passwords). Those accounts in the seclog you see waking up may well be examples of said hacked accounts.
It is likely that the few accounts that posted the threads
were compromised and the perpetrator was simply doing it for
a) attention
b) fake example of volume
It's unlikely that they would have actually sold the accounts and in reality, it's probable that it was simply a ruse to scam. When you have a number of accounts that are disposable, you would use them to earn more bitcoins - morally or not. What with loans being difficult to receive without a signed message, this is a trifling task that can potentially earn a sum of cash from an ignorant consumer.
