Ask HN: Wikileaks is available from Tor. Who's blocking it?

EDIT: Doesn't look like US ISP's (TimeWarner & Comcast) are blocking. Problems seem to arise at Swedish IPs (seems consistent with DDoS). Anyone have any idea why Tor and some VPN still get through?

It looks like the DDoS isn't the main culprit here. I assume that if the site is available from Tor, then someone must be blocking the site.

Can ISP's block Wikileaks? What is their justification if so?