How do I require commenters to include an email address without having to signup for intensedebate?!

How do I require commenters to include an email address? I checked the box in the wordpress discussion settings, but to no avail. I've searched around, looked through the blog settings here on intensedebate, and nothing... I can still post a comment anonymously, without even giving a fake email!

I read one Q&A answer that seemed to imply the only way to get this kind of functionality is to check "require commenters to signup for intensedebate". Is that for real? The only way to get decent control of my blog comments is to FORCE commenters to sign up for a third-party service? Seems like total overkill, and might just be enough for me to disable the service altogether (especially now that WP 2.7 has threaded comments builtin).

p.s. I tried checking "require registration to comment" and there's no indication of what people are even logging in to/registering for!!! (on the little pop-out form). Seems it would be reasonable to assume one is logging into the BLOG not into a third-party service...

I hope I'm just hopelessly confused or missing something obvious...

Update: To make things even WORSE it seems the are two, quite asymmetrical signup pathways for intensedebate. And suffice it to say that they're completely BACKWARDS! If I do NOT require users to sign-up, they can still do so by just throwing in a name and email, and checking the "signup" box. On the other hand, if I DO require users to signup, they must first click the link to signup AT intensedebate.com!!! A separate site! I haven't signed up with a fake user yet to see if I have to validate the email before I can comment, but even without that, this is exactly the kind of crap that will drive would-be commenters away!!! Bad news!