Xbox LIVE social butterflies have been complaining about the 100 friend limit for years. Microsoft has dodged the issue for just as long, but G4 reports the truth behind the friend list cap.

According to a “high-level Microsoft source,” the reason why we’re stuck with the cap is because of one game: Halo 2. The 5-year-old Xbox game still has a strong online community that continues to top the Xbox LIVE activity charts, but Halo 2 was built on an online system that doesn’t support more than 100 friends. Microsoft has stuck with that online architecture through the release of the Xbox 360 and it remains the same today. Because of Halo 2’s sustained popularity online, Microsoft has no idea when to pull the plug on the original Xbox LIVE system. It’s like having that old, dirty uncle living in your house. He’s nice enough and everybody seems to love the guy, but he’s clearly overstayed his welcome. And Microsoft has no idea how to gracefully kick him to the curb.

The Microsoft source also claims that they’ll be looking for gamers’ comments on the issue. So for those who absolutely, positively must have hundreds upon hundreds of friends on their list, tell Microsoft to pull the plug and stop playing Halo 2 already!