Robert Philip Hanssen, the former FBI counterintelligence agent, caused the worst intelligence breach in U.S. history.

Ironically, this self-confessed traitor considered himself a devout Christian. Throughout his 25-year FBI career, Hanssen told friends and colleagues that without religion, men were lost. When FBI agents held going-away parties at strip clubs near the bureau's headquarters, Hanssen refused to attend, saying it would be a sin.

When he was arrested on charges that he'd been spying for the Russians since 1985, those who knew him were stunned. His closest friends and colleagues said they could only guess why a man who seemed to possess such strong Christian faith would engage in anti-American espionage. In the Charlotte Observer, Philip Shenon speculated that he "must have been able to compartmentalize his life, deluding himself into thinking that espionage was simply an exciting intellectual challenge that had nothing to do with leading a good, moral Christian life."