Hoaxers engage in defamation, slander, libel, disinformation campaigns and criminal defamation.
A Predator Troll is susceptible to having psychopathic, narcissistic, sadistic and Machiavellian personality traits.

The Cyberstalking is deliberate, repeated, and hostile with the intent to harm.  Hoaxers and Predator Trolls are Cyber bullies that  intimidate, control, manipulate, put down, falsely discredit, or humiliate the recipient.

http://www.cracked.com/personal-experiences-2232-my-son-died-at-sandy-hook-conspiracy-nuts-think-im-lying.html

http://www.newsweek.com/internet-and-golden-age-bully-271800

What Kind of Person Calls a Mass Shooting a Hoax?