Chicken Invaders:

This map shows the geographical locations of hosted multiplayer games for Chicken Invaders: Revenge of the Yolk, based on master server data for approximately 400,000 matches. Color reflects density: gray areas received no games, followed by purple, blue, green, yellow and red (with red signifying the most dense areas).

Looking at the map, some people appear to live in the middle of the ocean, or at the default location at the center of the map. In reality of course, that means that these people gave a random location or no location at all.

Friendly hint: try not to do that.

The game uses the information you give to locate players near your current location. This maximizes the probability that you'll get a fast and reliable network connection, leading to an enjoyable and lag-free game. If you give an inaccurate location, the game won't be able to find any matches near you (so you'll end up always playing alone), or it will match you with people that in reality live very far away from you (so your network connection will be slow and unreliable).