GTA IV LEAKED! I DOWNLOADED IT! I burned it for my friend a week before release, it is PAL version (not NTSC) but you can still play it! Groups iCON and 1 0 1 have recently leaked the .ISOs for this game on torrent sites such as Bittorrent, and people are already playing it in single player AND online. If you get this I suggest not playing online, you may get banned :O. Reports/news to back this up:

Quote Originally Posted by https://www.theinquirer.net/gb/inquirer/news/2008/04/24/gta4-leaked-online
THE OFFICIAL RELEASE is only six days away, but hacked copies of Rockstar's latest opus - Grand Theft Auto 4 - are already appearing on the interwebs.

Retailers have been threatened with thumbscrews if they dare break the game's street date of April 29, even under intense pressure from gamers desperate to get their hands on what is sure to be the game of the year. So far, all have publicly avoided getting into trouble - but someone, somewhere, has been very naughty indeed.

Cracking group 'Icon' has taken credit for leaking the full 6.32GB disk image of the Xbox 360 version to Bittorrent. This is the PAL version - indicating that it's come from a UK or Australian source - and does appear to be the legit thing. The release notes for the game suggest that eager gamers don't play the game whilst connected to Xbox Live, to avoid the Volish authorities from picking up on the outrage and banning their British butts.

Word on the street is that this is a toned down Australian version, so if you really want to chainsaw hookers' faces off, you'll have to buy the real thing when it comes out.

Reports are also hitting the intertubes that an NTSC version of the game has shown up courtesy of '101'.

The leak has led to a flood of GTA4 video being posted online, with various online video sites hosting gameplay footage, the introductory trailer, and the inevitable deluge of cool stunts and glitches.
Quote Originally Posted by https://www.techspo*****m/news/29831-pirated-copies-of-gta-iv-hit-torrent-sites.html
With less than a week until launch, a PAL version of Grand Theft Auto IV began to emerge on torrent sites earlier today. Apparently, a group called “iCON” got their hands on a copy and ripped it, making the 6.32GB download available to all.

The leaked game will apparently play on either a debug 360 or a modded console and is only compatible with the PAL television format – which means people in Europe, Australia, Japan and parts of Asia should be able to play the file. This isn’t the first time a GTA title has been leaked early, as it happened to San Andreas also a week before release. It will be interesting to see what Rockstar does in response.