Why must I set Sensor in Google Map API request?

I was playing with the google map v3 API, and encountered this error, "The Google Maps API server rejected your request. The "sensor" parameter specified in the request must be set to either "true" or "false"." The sensor parameter doesn't give you any geo location capabilities it just lets Google know as part of their licensing terms with their data providers that the map is being used in conjunction with some sort of geo location functionality.