Rafe Colburn says it best: Tobacco companies more evil than you thought:

Tobacco companies found themselves facing the need to argue that some of the scientific evidence used to support laws banning smoking in public places is “junk science“, but quickly realized that a campaign focused on tobacco-related research would be dismissed as transparently self-serving. So they instead spent their money to a create propaganda campaign that attacked scientific research on many fronts, including research that supported smoking bans. The end result? The execrable Web site JunkScience.com. I’m sure John Stossel fits in here somewhere as well.