Board owners can easily customize their CAPTCHA to match the style of their own site. Visitors are presented with an easy picture-based test for them to pass, but automated bots are turned away.
It's easy to install (instructions are located in the file install.xml). There are millions of ways to customize it to your own liking, with more options on the way!
Someone just contact this person firstname.lastname@example.org
and after that they give you plugin for testing
Phpbb and SMF Team do this for your user..