The other thing you could do (to at least slow them down) is not let anyone post until 24hours after they create a customer account.
I do not believe that will help to stop spamming. Captcha on registration will help a bit, but for sure forum need to be changed. Unfortunately, there is no response from nopCommerce Team at this topic, so not sure if that topic got any sense to be continue.
What is interesting, I found a bug.
See this person: Annexclock34
- registered, had to post something, got karma 145, but only one post is available at profile. So karma is not reduced if post is deleted.
Another thing, adding points to karma by only adding new post and/or new topic, cause that on list named "Best rated members the last month" we have two spammers. Spammers as best rated members? Not looking well, don`t you think? If it is best rated members, it should be calculated from rating, not posting by the way.