Longer wavelengths require huge antennas to concentrate the energy at a distance. It would be probably very difficult to perform this attack. I also think that

Longer wavelengths require huge antennas to concentrate the energy at a distance. It would be probably very difficult to perform this attack. I also think that such energy density with relatively low frequency (~3 GHz) would disturb operation of computers, phones and other electronics, so it would be pretty suspicious.