The Restrictions on Use of Materials section appears to forbid users from running remix software like the Google Toolbar on their sites (emphasis mine):
No material from any WDIG Site or any Internet site owned, operated, licensed, or controlled by us may be copied, reproduced, republished, uploaded, posted, transmitted, or distributed in any way, except that you may download one copy of the materials on any single computer for your personal, noncommercial home use only, provided that (i) you keep intact all copyright and other proprietary notices, (ii) you make no modifications to the materials ...
Boy, I'm sure glad I never visit any Disney sites, since my browser does not and cannot render from an unmodified copy of the HTML: we have to mix it into something that will build a valid DOM, and that's what we cache.
I guess that's the end of pop up blockers. and user side css.