A note to new arrivals: This is one of the most popular pages on this site, for some reason. At any rate, if you came here looking for links to download SP2, try this one (or this one, if you prefer a simpler approach). The following is the original post that occupied this page.
This is dumb. Really dumb.
BBC News reports that File-sharers are offering SP2 over BitTorrent, a peer-to-peer file-sharing system.
File-sharing activists are using Microsoft’s key update for Windows XP to highlight the benefits of peer-to-peer technology.
A lobby group called Downhill Battle has set up a link using file-sharing software to distribute the SP2 update.
Microsoft told BBC News Online it was investigating the site.
Where do I begin? First, never download executable programs (including operating system patches) from untrusted sources. Never never never. I use BitTorrent regularly to download legal live music performances by my favorite “taper friendly” bands. But I would never (never never never) use it to download an executable program that could contain a virus or a Trojan horse program.
Second, the bits are already available on a legitimate high-bandwidth connection and as a low-speed download via Automatic Updates. BitTorrent is a great way of sharing files that aren’t available on an FTP server, but it’s a pointless waste when the files are already available to any and all comers with no restrictions.
Like I said, this is just plain dumb.
[Thanks to TechDirt for the pointer.]
Update: BitTorrent is a marvelous tool and a great way to share files over distributed networks. However, it isn’t necessary when the file in question is already available via a fast, readily available public server, as SP2 is. So if you came here looking for information about getting SP2 via BitTorrent, leave a comment and tell me why.
Ed Bott 
In the beginning, Microsoft had a bandwidth limit on the SP2 download. Many people wanted it, but not that many could download it, because of the Microsofts bandwidth limit. Downhillbattle wanted to prove that there are legitimate uses of file-sharing techniques such as Bittorrent.