While buying and selling accounts is hugely frowned upon by the community, it's not illegal. People just usually give negative trust to those people; though in this case it looks like the person looking for an account is using a disposable account anyway.
Q: I saw a guy selling Bitcointalk accounts. Why is that allowed?
A: Since we can't effectively prevent these sales (proxies, TOR, sales on other forums), we don't because otherwise we would be giving the users a false sense of security.