"Let's say somebody says right out, 'I'm going to kill you,' that actually is considered a lower threat then sending you a bullet in an envelope in the mail," Moyer said. "We're looking for bad guys. We're looking for body language, facial expressions, people who have a fixation on him that may want to come up to him and approach him."
Hollywood drama sometimes becomes real-life drama when bodyguard relationships turn hot and heavy. In an interview with ABC's Katie Couric last September, Heidi Klum admitted sparking a romance with her bodyguard after her divorce from Seal.
" I've known him for four years and he's been with my family for the last four years," Klum said at the time. "He's cared for our entire family, mostly for our four children. He's helped us tremendously. I trust him. I trust him with my children's life. He's a great man."
In 2011, TV cameras caught Kim Kardashian and her former Australian bodyguard in a lip lock while filming her reality show, "Kim and Kourtney Take New York."
Then of course, who can forget the most iconic bodyguard-client relationship portrayed in the epic 1992 romance thriller, "The Bodyguard" -- the story about a music star, played by Whitney Houston, who falls in love with her bodyguard, played by Kevin Costner, after he is hired to protect her from a stalker.
But Moyer said romantic relationships between clients and their bodyguards are not appropriate.
"You are not their buddy, you are not their boyfriend or girlfriend and the reality is you have to maintain, always, the professional barrier," he said.
Sometimes those relationships turn sour. Justin Bieber and Britney Spears have both been sued by their former bodyguards. Spears settled the suit out of court. That professional barrier can also be tested by celebrities with illegal habits or those who are simply looking for a hired thug.
"If someone has an alcohol or drug problem and they are expecting their bodyguards to jump in and fight -- not what we do." Moyer said.
For Bennett, who is also branching out into a music career, he believes the risk of being hurt at a Hollywood party is low, but said the expense of a security detail is well worth the peace of mind.
"If you are more in the public space, there definitely is more of a threat," he said. "But I mean, as long as I have my guys, I don't think I would be worried."