We actually have that in place already. Users with certain negative karma cannot participate in the gallery. 

Can you give an example? We're not able to reproduce that on this end. 

We don't allow our advertisers to use them, but there are thousands of ads on the site, so once in a while one slips through. If you can send details about which ad it was and which page you found it on, we can remove it. Thanks!

Sorry, PayPal is currently our only method of accepting payment.