I have a client who is asking about integrating captcha into their checkout? This is the first time I've received this sort of request. I've never heard of bots making purchases, but they said that this request came as a suggestion from their gateway provider. I searched around on your site, but only found a couple of forum posts, and nothing in your documentation. I found a reference to "fixing captcha images" in one of your changelogs, but I got the impression that this was more of a compatibility fix, perhaps with a gateway or CMS that provided it's own captcha.
Is there any way to integrate effective captcha into the checkout? I'm guessing that since all customization is client-side, that unless you provide this as a built-in feature, there is no way to do it. Please correct me if I'm wrong.