The USPS reportedly has some very expensive machines that can read letters without opening them now. I believe it was Russell Tice that said that, though I can'

The USPS reportedly has some very expensive machines that can read letters without opening them now. I believe it was Russell Tice that said that, though I can't find the specific source at the moment. But it's technical feasible and a desirable tool to get around being unable to legally open letters.