Long years ago, when I worked in downtown Washington, DC, I used to go for a walk at lunchtime. One day, I walked through the park across from the White House (now called Presidents' Park) and saw a couple sitting on one of the benches, holding a sign protesting something. Both of them were wearing aluminum foil hats on their heads, and the sign made reference to 'government radio waves' attacking them. Over the next few years, until my office moved to Crystal City, I would see the same couple, on the same bench in the park, and wearing what became increasingly thick foil hats. In 1985, when I was back in DC for a meeting, a walked by the park, but the couple was no longer there.