For most of the one third of Americans recently polled who think aliens have visited Earth, that believe is more or less harmless. But there are times when a perceived alien threat becomes deadly.

An example is the trial of Allison Lamont Norman, which began last week in Georgetown, Delaware. Norman is accused of killing two people and wounding four others during a shooting spree in April 2005.

Why? According to his lawyer, Norman believed his victims were space aliens who were trying to abduct his daughter.

Since the dawn of time, primitive man has often looked upon comets as precusors of disaster.

When comet Hale-Bopp appeared in the skies in 1997, many people were excited. But soon some UFO fanatics claimed an alien spacecraft was following the comet. Though there was no truth to the rumor, talk show host Art Bell repeated the claim on his late-night show "Coast to Coast AM."

The Heaven's Gate cult believed the non-existent spaceship was carrying Jesus, and that it was a sign for the followers to shed their earthly vessels and 39 people committed suicide.

In May 2002, six people were injured when 18 pipe bombs left in rural mailboxes in Iowa, Illinois, Nebraska, Colorado, and Texas exploded. The bombs were traced to Luke J. Helder, a 21-year-old college student. Following a high-speed car chase, Helder was was arrested in Reno, Nevada. Helder wrote that the bombs were "attention getters" designed to enlighten the world to his beliefs about paranormal topics such as aliens, ghosts, astral projection, and spirit channeling.

"I'm taking very drastic measures in attempt to provide this information to you," he wrote.

The article above was found on Google and was published originally on China View