Paranoia On the Rise

Say experts.

The post-Sept. 11 atmosphere and the war on terror have also increased levels of paranoia in the West, some experts said.

"We are bombarded with information about our alert status and we're told to report suspicious-looking characters," Penn said. "That primes people to be more paranoid."

Traumatic events can make people more vulnerable to having paranoid thoughts. Since the attacks, Penn said Americans have been conditioned to be more vigilant of anything out of the ordinary.

Plus, of course, you have the kooks who think the government was behind it.