I suppose they totally have that capacity, because cellular networks depend on fair play of thousands of devices sharing access to a part of the spectrum in a given area. Constant stats gathering has to be vital for detection of hardware faults and coverage problems in very complex city networks. Stations can even ask mobile devices to work as remote probes, and report immediate signal levels for each station they can receive. Operators have all the incentives to snitch on anything suspicious or broken to both the regulatory body, and the security services (who probably reply “oh, it's ours” most of the time).