Griefing has been around for a very long time. The current generation didn't invent it. Nor the previous one, nor the one before that. The fact that griefing has flirted with the online world and become noticeable as a subculture within human society doesn't mean that these forms of anti-social behavior are limited to merely online venues.
Some say it is the anonymity of the Internet and of MMOGs and virtual environments that particularly promotes this behavior -- but the physical world is full of insults, mockery, criticism, insults, bullying, belittlement and disruption, all for personal amusement and quite frequently without recourse, despite the fact that the perpetrators may have well-established and readily accessible identities.
Anonymity isn't the key factor here. It's just an incidental circumstance in a far larger picture. Violence among people, and particularly among teens is at a 30 year low -- some regions are reporting an all-time low.
Australian writer, comedian, singer, and television host Paul McDermott observed the the signs of it last century in a piece written for an Australian newspaper during his time as a columnist during the 1990s. In his column, titled The new aesthetic of aggression, McDermott observes, 'What if this is a trend? What if flick knives and guns become passé and ridicule becomes the weapon of choice?'
Apparently it did, and it has.
It's easier and cheaper, and in the physical world has fewer negative repercussions for the perpetrator. The small can make themselves feel large by belittling or impeding others "for the lulz" (for laughs, for kicks or for shits and giggles -- all phrases dating back many decades).
Working for a regular corporation a few years ago, I had not just one boss, but most of the company officers and executives were, essentially, griefers. Had the phenomenon of griefing online really come into their sphere of attention, they would have been off down to the IT department to ask "How can I get me some of that action?"
Men and women, from their 20s to their 60s -- as ordinary people as you please, in other respects, but most definitely griefers. Think back. The odds are you've worked with or for more than a few people like this over the last decade or two or three. You probably have at least a few war-stories about their mistreatment of others.
We like to think that griefing and similarly disruptive behaviors are strictly online phenomena, because we can rationalize that it's just those wacky kids, or that there's somehow something magical about the medium that causes us to behave out of character.
That's a whole lot more comfortable than the truth of it. Griefing has only ever flirted with activities in MMOGs and virtual environments, and while it is most obvious and prominent there, it is only a comparatively small part of a broader phenomenon that transcends the demographic boundaries of our species offline.