Craigslist Scammers

I like scanning dallas.craigslist.org every now and then for something I’m in the market for or just looking for something that might be a great deal. Being a techie and keeping up with the used and new market on equipment, it’s easy for me to spot the “too good to be true” CL ad.

I’m also tired of seeing ads for items well outside the reasonable range to be for sale in the DFW CL area. If I want to search for a boat around the coast in Texas, I’ll select the area in CL and search. I don’t want to see a Boston Whaler for sale in Maine listed in the DFW listings. The majority of the ads I’ve seen posted from outside the area are scams anyway, usually having an email address posted in the ad. I’ll copy the email addy and check it against Google and viola! I’ll usually see the same exact post in SF, LA, NY, etc.

I’m not sure how to cut out the scammers completely, but I do have a few ideas on how to cut it back somewhat.

1. Create a database that stores every poster’s IP, email address, and posting area (DFW, SF, etc) (if one doesn’t already exist)
2. Cross reference the posters’ IP address, email address, and posting area at the time of listing.
3. If during the cross reference, the IP or email address comes up with multiple area postings, flag it as “cross posting” to help local users identify the cross poster. Also create a flag in the above database that the email and IP address used has “cross posted” and track the # of times as well.
4. If during the cross reference the IP or email address comes up with being a “cross poster” > # times, ban the email address for a specific time (1 week). If its a second offense, ban the email address for 30 days. I realize scammers use multiple addresses, but this would at least make it more difficult.
5. On a monthly basis, the database could be queried to report all email addresses and IP addresses that have the “cross posting” flag along with the # of cross postings. As a double check, the IP addresses flagged could be queried against all posts to determine the ratio of “non-cross posters” to “cross posters”. This would help create a blacklist of IP addresses based on the ratio.

I have no idea what’s in the works at CraigsList, but I think the above could be implemented fairly easy and reduce some of the posts by scammers and spammers.