WWW- Fueled by the promise of anonymity and instant gratification, a growing number of people are using the Internet to wreak revenge, online safety experts say.

Cyberstalking has expanded enormously in recent years, with WiredSafety, an online safety group, monitoring about 1,600 harassment complaints a month – twice the number of five years ago.

In recent weeks, suspected Halloween sex-fiend Peter Braunstein thrust cyberstalking into the city’s consciousness.

“In real life, you have to worry about someone spotting you if you stalk them,” said Parry Aftab, founder of WiredSafety. “Online no one’s going to punch you in the face.”

A look into the twisted fugitive’s past revealed that the 41-year-old journalist had been busted for terrorizing an ex-girlfriend in the months before he allegedly molested another woman in her Chelsea home on Oct. 31.

He posted nude photos of his ex on Web sites, eviscerated her on blogs and created online announcements indicating she was seeking sexual encounters. He also bound her to a chair with tape and brandished a knife. Eventually, he pleaded guilty to menacing and was sentenced to three years’ probation.

The penalties for cyberstalking are little more than a slap on the wrist, Aftab said. “You can get law enforcement involved,” she said. “But most of the time, the person will just lose their account with AOL or whomever.”

E-mails or instant messages are the most common form of attack, Aftab said. Creating a Web site to discredit a former paramour or posting humiliating comments about him or her in a chat room also are popular ways to terrorize someone.

One local woman, who asked not to be identified, said she became a virtual victim after breaking off a relationship with a man.

Along with creating a “hate Web site” under her name and posting photos of her online, the woman said, “He sends E-mails to anybody and everybody associated with me. He says sexual stuff about me, very nasty stuff.”