We're seeing some issues with the main https://foldingathome.org/ web page. We have some ideas, but it's late here (11pm pacific time), so we'll have to wait for IT to get in to work in the morning to get a fix implemented.
For now, if you see "Access Denied", please try to reload the page: that should yield a working page.
UPDATE: 9am Dec 9
Stanford ITS has sent me an email saying that this is now fixed, but it doesn't look like that to me (although it is better). I have informed them that it isn't and am waiting on them. For now, you can hit retry until you get the page you want, but clearly this is still broken badly.
UPDATE: Looks like this has now been resolved.