22
Yes, they've all been hacked including the default one with XOOPS as well as the reCAPTCHA hack for XOOPS. The reason that I use reCAPTCHA is because it's the only one I've found that works for people of disability (particularly sight) which is a requirement for most of the sites I work on. The other alternatives suggested, including the new reCAPTCHA versions, require somebody who isn't sight disabled.
We'll see how Barry's 2-step registration tip goes for now (none new since implemented yesterday) and I'll look at implementing the StopForumSpam piece in the future because I'd like to have a single-page registration solution for users.
We're also using it on the xForms contact us module but they don't seem to be using that yet. I must admit I found it interesting that somehow these folks have setup scripts that allow somebody in some other country to sit at a computer screen and "solve" these reCAPTCHAs for their spam bots at $0.05 each.
And no matter how hard one might try, it's pretty hard to keep folks from figuring out that you're running a XOOPS site. Besides changing code in every template and using the xoRewriteModule to change all the URLs, there are a number of other signatures that would be difficult and/or time-consuming at best to remove.