Richard Linklater's 1991 film "Slacker" touches on a number of persistent conspiracy theories. Many of them, such as moon landing hoaxes and JFK assassination plots, are still bandied about today, especially on late-night talk shows like Coast to Coast AM. If you watch this clip, you'll see an example, but there's a part about global warming, too. Today the conspiracy nuts think that global warming is the hoax, that somehow scientists are pulling the wool over the eyes of the public. This clip shows that around 1990, the conspiracy needle was really pointing the other way, with the government covering up global warming. "Greenhouse effect... by the way, they discovered that in the '40s."