Definition of a Sexual Predator
From Wikipedia

The term sexual predator is used pejoratively to describe a person seen as obtaining or trying to obtain sexual contact with another person in a metaphorically "predatory" manner. Analogous to how a predator hunts down its prey, so the sexual predator is thought to "hunt" for his or her sex partners. ..According to the NBC news program Dateline, as of January 2006, law enforcement officials estimate that as many as 50,000 sexual predators are online at any given moment.