Technically, I would say almost* everyone on Blockland has been a "Cyber Bully"** at least once. In fact, most people on the internet have a "Cyber Bully" in their life, anonymity and all makes it soooooo much easier to forget their is a human being, the walls of social acceptablilty dissolve at the might of the internet. You can tell anyone what you think of them, without a major care.( as in, worry about a major social backlash offline)
*Excluding new people and people who do not talk.
** I really, really hate this term, it just seems so idiotic.