Every cell phone doubles as a cell tower.
However, are the phone companies going to pay you any money for helping them route other peoples' information through your phone?
Also, we've heard about hackers creating fake cell towers. It should be even easier to create fake LTE's that can scan lots of data as it passes through.
And if you don't have the latest/greatest phone you may never be able to use it if it is constantly being bogged down by other peoples' traffic.
I think it was already determined that those towers were put up by some Governmental Unnamed Agency or more than one.