Dynamically Typed has a new post today with a look at something that is plaguing web site admins for a good while now - automated form spamming.

Anybody who develops or maintains blog software is likely to be all too familiar with the problem of comment spamming. I recently became the victim of spamming through a 'contact' form. The results of the contact form are emailed privately to a member of the site, and not displayed on the Website. However, this didn't seem to deter the spammer - they were using an automated bot to send hundreds of them.

He mentions two of the options that several sites have started to use - Bayesian spam filtering and the ever popular CAPTCHA images. I also likes that he looks at the thought process behind commenting and community on a site:

Allowing your visitors to contact somebody or submit a comment adds communication and community to a Web site, at the expense of increasing the opportunities to spam you. It is a paradox that we want this functionality on our websites, even though we know that we can't trust all our users.