how do you know a trade is a cheater before trading with him?
 

are there black lists somewhere that are a consensus ?

i think damageX has a blacklist...
but just search for the suspected domain name on google and usually you'll find links to boards/threads about him, if he's cheating...

Some boards have cheater exposure forums, you might wanna check them.

Howmuch i remember someone has made site about blacklist in industry but cant remember the name.

Try this
http://www.cheaterhell.com/index.php

Doesnt choker keep a shitlist?