To constuct a cell tower or anything else for that matter over a given height in most areas require a local zoning permit. Plus annual payment to the land owner.
I’m not sure they are talking about ACTUAL towers - just what is perceived by your phone to be a tower. Could be some transmitter in the black van parked across the street from the local KKK or Islamic prayer meeting. Or perhaps a transmitter hidden amongst all the other antenna on an actual tower. I’m just guessing though.