There is scam thread.

Is there a way to notify the community of bad buyers?

Up to you. As long as you like here and lighthouse, my friend.  :)

I don't think that should be a requirement. I've been happy trading here just fine using Lighthouse for escrow.

In order to bring more liquidity for traders/investors/miners with buying/selling-demand >=500 PTS, I have created a skype group. 

Skype ID :PTS/Trading/500+ OTC

For all who would like to seriously buy/sell PTS,  please.

1> Make invitation,  have me connected with you  first.   

2> Real names represent respect and trust, highly recommended.

3> Escrow agent with reputation in the BitShares community is highly welcome.

My name is Bo Shen, an administrtor of bitsharestalk.org