Hi Richard,
Unfortunately captcha is not available in "web forms" and I believe it will not be implemented in the near future. The reason is simple - our application produces HTML and Javascript code only, which allows web forms to be inserted into any web page. This process is easy enough, so people with no programming experience will be able to do it.
Captcha on the other hand will require server-side code, such as PHP, C#, Ruby, Java and non experienced users will have a hard time implementing it. Also, because there are so many programming languages, we simply can't support a captcha implementation for every single programming language that is currently available.
So if you want captcha in your web form, we suggest looking on a web for a suitable captcha implementation. There are many available solutions and integrating them with our web form should be a quick and easy process.
Thank you
Victor