http://thepiratebay.org/

for those that don't know thepiratebay.org is a popular torrent listing site. torrents are the preffered method for sharing such things as music, movies, games, etc. in light of the leak of xbox360 versions of gta4 they changed their front page. clicking on the image on their front page brings one to the listings for downloading gta 4 for the 360.

I do not condone piracy in any way. i just thought that this would give a good indication as to how big this is.

the pirate bay is one of the holy sites.

I just checked a private torrent site and it's at 8,404 (counting completed downloads and seeds). I'm guessing when all is said and done they'll have at least 11,000 downloads and that's just one site. But that still pales in comparison to the biggest PC games on that site:

Crysis: 56,429.
CoD4: 46,069 
PES 08: 45,285
C&C3: (all editions): 89,014

there was a thread asking if the torrents will effect sales (i dont feel like bumping it) but obviously it has. Of course it wont look like it has because thousands is nothing compared to millions but still those thousands are revenue MS wont get... =(

 Poor MS.  They are really suffering, arent they?

If I was guessing I'd say that there are probably 250,000-500,000 illegal copies of GTAIV. But who knows how many of those people would have bought it legally, I'm guessing though a higher percentage would have than the average pirated release.

Here's another one from a few years ago:

They do quite a few: http://thepiratebay.org/doodles

with this you can see how fearless they are :D, that's the only place i can still find Marvel comics to download after Marvel threat to sue everybody in the world that posted online comics from them (I'd buy some of them but please ... let's be realistic I'm in freaking Chile)