You may remember that last year some nut was arrested for mailing bombs to prominent Democrats, media outlets, and opponents of Donald Trump. Less than a week after the bombs went out, a suspect was arrested. Almost immediately, video turned up of him at a Trump rally, wearing a "Make America Great Again" hat and chanting for the camera. He was soon tried, convicted, and jailed. End of story.

But it wasn't the end of the story. The investigation into the bomb incidents focused attention on an almost unknown federal surveillance program—one that poses a direct threat to the privacy and constitutional rights of every American. It's called the "Mail Cover Program" and it's run by the U.S. Postal Service (USPS). Yes, even the Post Office is spying on us.