Simple and effective CAPTCHA

This is probably the simplest and most effective self-contained CAPTCHA plugin yet. HumanCaptcha uses a very simple but powerful approach to impede bots: ask a simple question in English (or other language) – provide the answer, e.g. “Thursday, Friday, Saturday. What comes next?”, “What color is grass?”, etc.

It works! and you can add your own questions to the short list provided. This means bots don’t stand much of a chance, as they would have to be able to cope with random examples of English semantics instead of just relying on brute force OCR, code weaknesses, or the very limited lexicon required for simple math problems, none of which is very effective against bots any more. This strategy seems to beat them all, and it’s customizable too.

Issues with this plugin at the moment include (v1.4):

1) no option for the Reset password form
2) problem appearing on the Comments form in some themes
3) problem handling some special characters like “quote marks”
4) no option to export/import sets of questions and answers
5) lack of international support (i.e. multiple languages for the human visitor to choose from, with related sets of questions)
6) no ip log of frequent offenders or related ability to temporary block them

These few issues will hopefully be resolved in time, but you should try it out and see how effective and easy it is anyway. Watch it instantly kill your registration form spam.