Deffintly, that is ahuge liability for a site to take on, Paypal or credit card is the only way. Don't send cash, don't send money orders, atleast with paypal and credit cars, you have a lot to fall back on incase there are a few [censored] on CEG/ lurkers who suck.
What about simply not allowing classified ads to "non memebers" liek most other sites do?

AS moderator of classifieds, I can always delete those ads form the non memebers...although some people who are non memebers or just joined to post the ads could have some great things up for sale.
...and are active members list isn't in the hundred or even thousands like Vortex, focal jet, and others, though.
