A harassment prevention order is similar to a restraining order. It prohibits someone from engaging in certain activity. Unlike a restraining order, however, there is no special relationship between the plaintiff and the defendant.
Oftentimes, the question is can you get a harassment prevention order based on someone's words. Generally, no. Free speech is protected by the First Amendment to the U.S. Constitution. There are two specific exceptions to this rule:

1. Fighting words; and,
2.True threats.