Note that senior and even hero bitcointalk member accounts have been sold. Wobber today is not necessarily the same person who created the wobber account in 2010.
Onkel Paul
is that allowed?
Yes. Prohibiting it would not work anyway, and disabling accounts based on sell/buy suspicions would probably do more harm than good.
So if you need to rely on an account holder's identity, use another method of identity verification. PGP signatures are a good option.
Onkel Paul
And why you think that selling PGP signature is somehow harder than selling a forum account?
You can't change it, true, but there might be more than one holders at any point in time.