I have seen some spam filters that have layers. The first layer is captcha, which blocks most bots. Google recaptcha is very useful in this case. I don't think this will block any human user. In addition, users don't have to enter captcha every time once it determines that a person is not a bot. For reference: https://www.google.com/recaptcha/intro/index.html
The second layer is letting users to report spams, or having some kind of rating system (reddit). This blocks diligent human spammers. In particular reddit's rating system is smart because it requires no moderator; users actively downvote bad comments and upvote useful ones. I generally don't like keyword-based spam filters because they take time to maintain a good keyword list and are easy to block legit users. On Tue, Jul 14, 2015 at 9:09 AM, Oon-Ee Ng <[email protected]> wrote: > On Tue, Jul 14, 2015 at 3:43 AM, Johannes Löthberg > <[email protected]> wrote: >> Not all spam is automated , so just requiring a CAPTCHA wouldn't be very >> useful. I think a slightly better approach would be to add the comment to a >> queue if it fails the spam filter, and require a TU to approve it. > > Seems like a lot of unnecessary work for TUs though. Maybe it would be > better for maintainers approval to be required for posts that fail a > spam filter (they could just ignore it). Even if its not really spam, > its probably aimed at the maintainer anyway.
