If we really needed to know where they were, we could always find them ourselves and make our own database, as we do for fixed and mobile speed camera sites. But where as that's useful to avoid the thieving bastards, the mast locations are only of interest to the paranoid, to try and claim compensation for their imaginary 'radiation' caused ailments. Of course the TV masts putting out megawatts are always ignored, as hypochondria soon seems to clear up when you threaten to take away their 42" plasma.