I have never traded with anyone on this site, but I was reading through this thread and wanted to offer a few experiences I have had from other sites and some advice for those that got scammed.
I trade quite a bit on bluray.com and highdefdigest.com. We had members on each site that had around 100 feedback of great trades. These were members whom everyone had dealt with, knew by name, even knew their phone numbers.
At the beginning of this year, these members went renegade. They agreed to deals (one member did it with about 30 members, the other traded with over 60), then never sent what they agreed to send. (their names are Keith Roberson and Mark Sommer if they try to trade here). They decided to cash in their years of good trading, friendships, and great feedback record for a quick score or quick buck.
Times are hard right now and people are doing awfully ridiculous things for money. It looks like this website is facing the same exact things. Just because these people were great traders then, does not mean they will not rip you off now.
I was ripped off of 3 blurays I sent to one member, the guy that ripped off 60 different people, and never received a thing.
The good news is, agreeing to a deal online is a binding agreement/contract. Save all your PMs, emails, and delivery confirmation numbers.
Best things to do is contact the authorities. You start with the authorities in the area of the person you traded with. If these scam artists, cause that is what they are now no matter what their past is on this site, live in Phoenix, contact the Phoenix Police Department. Be honest, tell them you have all the information, tell them this person has been scamming multiple people, BUT BE POLITE.
Next, fill out a complaint with the Internet Crime Complaint Center. It is very easy to do. You can give them all your PMS, emails, and everything. It is an easy form to fill out and will get a record on these scam artists.
You can fill out the complaint form here
http://www.ic3.gov/default.aspx
Be diligent, but be polite and honest with the authorities. At this point, this is all you can do.