The Cascade fallout was one of the most hilarious things I've ever seen happen online, glad I was around for it. So many people freaking out as websites crashed and spoilers kind of trickled in from it causing people to flip out (I didn't read them, though, I was one of the few that got lucky and was able to DL from Megaupload before it went down).
Was just all around an amazing experience.
EDIT: As far as I know, the extent of the damage was thus:
Newgrounds: Crashed for several hours
Megaupload: Crashed for several hours
Streaming sites: Several went down for an hour or so
Mediafire: Slowed to a crawl (sub 5 kb/s) for everyone for about 2 hours
Fileserve and Rapidshare: Crashed for about 15 minutes and then had sub-30 kb/s speed for the rest of the day
Homestuck effectively DDOS'd the internet that day. And it was glorious.
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