I want to avoid spammers putting advertisements and curses [into a forum]. What is the best way to do it? Is a 'captcha' a good way to do it with 100% reliability? Is blocking IP addresses a good way?
I have found that a combination of the following works well:
Note that none of the above really tackles the issue head-on, which never really works. I believe it's better to manage the users before they post rather than clearing up after them.