The Mollom Ruby SDK by Joren De Groof allows to evaluate quality content via API. Usage demonstrates how captcha can determine if a user is spam. Additional code could remove the spammer if content is unsure.
In an age where end users and developers alike are more conscious about IT security than ever, it’s little wonder that more focus is being put on finding more robust authentication methods than the simple password.
If you run a website, like many of our readers, and you have an account system, you probably have problems with spam. One of the main sources of spam is users who register using disposable e-mail addresses. These can be generated by spammers programatically, using services like the Guerilla Mail API I covered previously, and used to make tons of accounts to try to get blog spam through. If this is a problem for you, the DEA Filter API can help.