Right now, I'm relying on Akismet [1] to automatically filter spam, which is a really good service. It's built by Automattic and they've had years of spam data to work with.
I haven't thought about forum slides, but that's pretty interesting too. I don't think Akismet could detect something like that. Of course, you can do it with moderators (you can make it so that all comments must be approved; or you can auto-approve and delete the offtopic ones later), but an automated way to detect that would be cool.
This is the long-term research plan I have; maybe we can even do away with Akismet. Spam is one of the hardest problems to solve, so it'll be interesting. But for now, I'm relying on Akismet until there are fewer and fewer core features left to implement.
On my blog I ask a random question that any of my readers would know the answer to. This makes sure they actually read what they are commenting and I received zero Spam so far..
Be aware that Akismet is a problematic service to use in the EU, because you might be sending private data over to that company. Akismet can be used without that metadata, maybe you do that already, just something to look out for
You could try to filter spam with a simple bayes filter for a start, good idea anyway to have a solution inhouse.
Perhaps you could build in a 'self-learning' feature built off the results of akismet such that one day you can provide an alternate spam system altogether.
I haven't thought about forum slides, but that's pretty interesting too. I don't think Akismet could detect something like that. Of course, you can do it with moderators (you can make it so that all comments must be approved; or you can auto-approve and delete the offtopic ones later), but an automated way to detect that would be cool.
This is the long-term research plan I have; maybe we can even do away with Akismet. Spam is one of the hardest problems to solve, so it'll be interesting. But for now, I'm relying on Akismet until there are fewer and fewer core features left to implement.
Thanks!
[1] https://akismet.com/