It seems that nim getting quite popular and spammers already found it.
So time to kick them out.
Any imaging lib for nim? i will develop a captcha for it.
I run a forum a few years ago. Most effective solution was simple puzzle plus e-mail blocking based on black list. You should consider implementing support for this:
I hate them all. I understand that spam is annoying, but as long as I'm reading here, there was a few spam. It may become more, so why not having a few more users with the delete first post right? Or add a functionality that users can report spam. If the spam was reported the post will no longer shown to the user. If more than N users have reported the post, set it to invisible and notify a moderator to have a look at it.
Just my 2 cents and sorry for the rage angainst all these verification mechanisms.
One effective way to prevent bot spam that doesn't require any user interaction is to create a honeypot field. The basic idea is to create a hidden field that looks like a submission field for signup/comment posting, so bots won't be able to tell the difference.
You can read about it in this stackoverflow question or this blog post.
It seems to work pretty well for filtering out most bot spam. The comments in that blog post also have some good ideas to make the idea even more effective.
I agree with pyloor somewhat, too many obstacles is not a good way to increase forum activity (and simple non-nim related questions might work in general, but that doesn't mean our troll isn't dedicated enough to get around it).. deleting a few posts each morning doesn't seem a big enough burden to justify that (give more people moderation power to delete them and you won't have to deal with it as often).
Also.. there's like one troll on these forums that keeps coming back.. he's always posting the same things (kitchens, tickets, etc) and he leaves the contact info.. if he's trolling us, it's fair game to troll him back right? What about writing a spam-bot that calls/emails the contact info he leaves us with endless streams of gibberish.. if the consequence of trolling us was getting a taste of his own medicine he might consider this place not worth the effort. (I know it's probably not worth anyone's time to actually write that software.. still, gotta wonder if it would work).
Anybody checked the IP of that spammer? Probably it's as easy as just not store comments if they come from his network / IP. It may also help to add a field into the form which gets changed by javascript when the page is loaded and if not changed will not save the comment. This way spam which is not send from a browser (but by curl post for example) gets blocked.
That said... I think by far the best option is to moderate the first x posts of a new user before they can post without moderation.
I'm not sure if it's bots doing the spamming, it might actually be real people. Would a bot really be able to crack our captcha?
Because of that a honeypot wouldn't work.
Moderating the first post sounds tedious, and does not scale well.
Giving users the ability to flag a thread as spam might be best, perhaps even flag as abuse. Then you guys will also have the ability to flag threads which abuse our community guidelines.