how is this ZIP code being sent?

Is my Mac laptop using cell tower information to calculate and transmit my location to third parties? I believe the answer is yes.

Here is my evidence. I cleared recent history from Firefox, selected private browsing, then typed “Msn.com” into my browser. Then I looked at what was stored in my cache (using about:cache), and I found this entry (see above).

This entry is a message from my browser to msn.com with whatever data can be passed along. Notice the “euid” field is empty. That is good, I am using private browsing. Then notice it is passing back my zip code as 07024, and my local news provider as WNBC. Is this coming from my IP address?

The answer is no, it is coming from cell tower location information. How do I know this comes from cell tower rather than my IP address?

The zip code transmitted is  07024 (Fort Lee, NJ). However I live right across the river is Washington Heights, upper Manhattan (below is the view of New Jersey from Washington Heights).  Often 911 calls via cell phone from my neighborhood get routed to New Jersey by mistake due to our close proximity to NJ cell towers. So my zip code is not coming from my IP address, which comes from Time Warner, hence it should be a NYC zip code, not a NJ zip code. It seems to be coming from cell tower triangulation, being collected and passed along by my Mac laptop :(

View of New Jersey from Washington Heights