In late 2007, I started administering a webserver for the computer science club on the Cal Poly Pomona campus. Shortly after, people wanted web forums. After I installed them, I noticed that they seemed to be getting a lot of spam, spam which I had to delete.
I'm a fairly lazy person, and would prefer not to have to manually delete things. Being a sysadmin, the most obvious immediate solution was to write a script to do it for me. sfs came from that.
Simply, sfs is four functions that interface with a website called stopforumspam.com, which collects data about forum spammers, and offers an API to access those data (as well as one to add to their collection).
You can download it here: sfs-0.1.1.tar.gz. There is a small example script in there to show how it works. Pretty much everything is under an MIT license, if that is important to you.
Feedback and bug reports are welcome: email me at kacarstensen at csupomona dot edu
Lots of people like to insert code in the registration functionality of their forums to check users when they register, and deny registration. This is a fine approach, and this library will likely be of little help to you if you use it. I personally don't like that (I'm not a huge fan of having to remember what was modified when they release a new version), so I opted for a script that talks to the database directly. I'd imagine that the library would be of most use in a similar application.
(a good approach might be to combine the two: known spammers are stopped at the door, so to speak, and if the ones who aren't known spammers when they register turn out to be known later, the shell script can get them)