Created 21 January 2007 Spam sucks. Any site which allows unauthenticated users to submit forms will have a problem with spamming software (spambots) submitting junk content. A common technique to prevent spambots is CAPTCHA, which requires people to perform a task (usually noisy text recognition) that would be extremely difficult to do with software. But CAPTCHAs annoy users, and are becoming mor