WebARX, by default, has the reCAPTCHA feature turned off. You can pick to which pages you would like to add the reCAPTCHA; login, register, forgot password, comments.
If you turn this feature on and have a different plugin installed that has the same kind of functionality, you may get locked out of your site. In this scenario, you have to delete either plugins.
If you would like to delete the WebARX plugin, click here to find out how.