Hmmm - years and years ago I used to engineer as an undergrad for WXPN AM and FM "The Radio Voice of the University of Pennsylvania" - we had limited-power AM transmitters located around campus and the only danger I recall from that setup was that once in awhile the signal would hop to the trolley wires and broadcast to parts of Philly where it wasn't supposed to be - can't believe that wireless internet would be more hazardous.......