I think that's a lost battle now -- the Terms of Use / Privacy Policy of pretty much every online service, important or otherwise, says the same thing. For example, from HN's own terms of use:

> You agree that Y Combinator, in its sole discretion, may suspend or terminate your account (or any part thereof) or use of the Site and remove and discard any content within the Site, for any reason, including, without limitation, for lack of use or if Y Combinator believes that you have violated or acted inconsistently with the letter or spirit of these Terms of Use.