This is information that your readers may find interesting. I had been having intermittent problems with the keyless entry and ignition system on my Toyota Yaris. I called the AA and they said it may be interference from a mast etc, although there was nothing in the area.

A few days later the police called and asked if I'd had problems with my car and I told them I had. The police said that several neighbours had reported similar problems and the police suspected that someone had left a device in the area to interfere with keyless entry systems so that people wouldn't be able to lock their cars. The perpetrator then steals from the cars overnight.