1. I completely agree. 2. Well, there is a point, it blocks those people who just type anything in the registration forms. But I agree that it's too easy to tri

1. I completely agree. 2. Well, there is a point, it blocks those people who just type anything in the registration forms. But I agree that it's too easy to trick. Performance shouldn't be a problem. Only registring users need to have their email addresses checked. In your example, every page load = a dns request, which isn't a great idea. As one registration = a dns request, this load should be quite easy to handle for the webserver.