I guess it's not as huge as you might think though - here's one of the FAQ's on the site:
Q: Isn't the Web too big for anyone to be able to download it?A: If we consider the whole World Wide Web, yes it would be time-consuming to download it. Recent statistics from Google estimate that there are approximately 74.3 billion pages on the Web. If we assume that each page has 10.4 Kb on average, that is already 673,200,000,000 Kb, or 673.2 Terabytes (Tb)!
Our detailed review, however, has found that 92% of those websites are pornographic or gambling related. Once we removed these, the size of the Web is reduced to 8% of the initial volume, eg 62.8Tb.
As a next step we eliminated the illegal MP3 and movie files as well as the distracting YouTube videos. This further reduced the size of the Web to 3,444 Tb, which is the size of our file collection.
I think they meant 3.444 Tb though, in that last section. Anyway, I'm really not sure who would want that... but I guess they're getting some business somehow.
You probably are wondering what I was wondering... What about blogs, etc that update frequently? Well, apparently they have "update CD's" to download every day... Not sure how this integrates with the rest of it but I guess maybe they have some sort of management system to sort of add it in to the original files.
The things people come up with these days... :P
Update: apparently there are a significant number of people that want it, cause the downloads are disabled right now due to bandwidth issues. Oh well, guess I won't be able to get my copy of the web just yet... ;)