Since the Internet became a major thing and people could do it without fear of saying it right to someone's face :/ I think socially the Internet has made us crueler to eachother.
It was a thing before it but I think now its almost semi socially acceptable.
This is an actual thing psychologists talk about. The official name is the Online Disinhibition Effect - but the commonly used term is the GIFT, or Greater Internet F**kwad Theory, as coined by the folks from Penny Arcade
This idea, that anonymity breeds bad behavior, is Older Than Dirt: Plato, the Greek, talked about in his world The Republic
the story of the Ring of Gyges - a story about a man given a ring that would make him invisible, and what that did. HG Wells' The Invisible Man
talks about such things, as well.
The basic idea is, unchained from the possibility that they might have to suffer real-world consequences - loss of job; the scorn of friends, family, and others - people see absolutely no reason not to be a complete jerk, because there is nothing for them to lose.
There is one thing to note - the GIFT can cut both ways, though GIFT is usually ascribed to the negative aspects of behavior. But some persons, knowing that no one will know who they are, actually will speak openly and honestly about matters that they might not feel up to talking about openly in the real world.