Interesting reading can be found by looking at:-
www.rarechinesecoins.infoThen select 'Top Chinese Numismatic sites' then click on 'Blacklist', found in a list on the left-hand side.
This gives a very very comprehensive list of fake coin sellers/offenders.
Seriously, this has reached the stage that the whole Chinese export market of 'collectables' is being tarnished by the few. China now has a terrible reputation. It is bye the way, illegal in China to post coins by mail. If they claim they are coins, then they are breaking Chinese law if they post them, and the important word here is post. So if we can find out who they really are, then who knows, maybe Chinese law will do something (unless they have been bribed of course).