I have just gone through this... A big problem is that the owner complains and the credit card company charges you a penalty and if many get through they can dump you.
At first, I banned the IP address when someone tried 3 times unsuccessfuly. That worked for about a day then they would come back and try again, but with different IPs. Must be real people and not a bot. Then I tried something different... if someone tries 3 times without success, I flag the IP address and then when they submit a donation, I return the page that says it failed (and I do not even send it on to the credit card company). I also flag the entire subnet to make it harder to get around. Most are from south america and china.. should probably reject any non north american ip.. A few people have called me and told me they tried to make a donation and they get rejected for no apparent reason.. in which case I take the donation by phone. I went about a month without 1 complaint so it might be working! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Order the Adobe Coldfusion Anthology now! http://www.amazon.com/Adobe-Coldfusion-Anthology/dp/1430272155/?tag=houseoffusion Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:354463 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/cf-talk/unsubscribe.cfm