I don't think either of your proposed options are legal/possible. afaik this geo data isn't sold to a single party, and is collected through so many various ch

I don't think either of your proposed options are legal/possible. afaik this geo data isn't sold to a single party, and is collected through so many various channels purchasing them all would be quite expensive. As far as making your own cell tower, I would love to know if this is even something a non telco company can do. I doubt creating any blocks for specific content would be possible or legal as well. How would you block https traffic, and how would you determine who is an employee and who is not? This tracking is a result of allowing visitors to bring personal devices on prem. As long as they are personal devices administered by their owner I don't know what could be done to mitigate this. The problem still exists if all phones are put into a faraday cage when they arrive at the site. Instead of tracking users at the plant they just track users who 'go offline' at the drop off site. Getting employees to stop bringing personal devices is the only way to actually quell this fear. Even the US military has an issue with Strava run logs leaking data about the movement patterns in their bases.