If you even had the slightest feeling of "wanting to buy this piece of--" here's why you shouldn't:
1. It's against their TOS
2. It's possible that the seller can get ahold of the account again using the credentials which he own
3. There's a 99.9% chance that you're transacting with a scammer because no one on his right mind will sell an account connected to his own identity
It is illegal.
With all these ICO's requesting KYC without knowing who are behind them investors/bounty participants are sharing their info with strangers and some of them are scammers, when I see topic like this only thing I can see is - very shady activity.
Be smart guys, don't buy verified accounts, other people's credentials or anything like that because it is illegal and be very careful with sharing such info's over internet, one day police may knock on your doors
