Badbear, administrator of bitcointalk has started a campaign against account sellers. If you previously bought an account for personal use you're safe! But everyone posting with multiple identities with an intention to sell accounts is at high risk for a ban at the moment. I would suggest you to avoid account trades withing the forum because if you end up buying an account created by an account farmer there's a high possibility this account will be later banned/deleted permanently.

2 thinkgs to keep in mind:
1. Buying accounts has an even higher risk now, be sure to deal with trusted people, use escrow and never risk too much money.
2. Trust no one, if an account seller tells you that it's safe and allowed by the forum rules, you still don't know how he got the account. You shouldn't believe him if he just tells you the account wasn't farmed since this could get you a bad quality account with a high chance of being banned. Always ask for accounts with decent quality posting. If the account doesn't meet the promise ask for your money back or leave negative feedback.