I’m old enough to remember when to hear that something had ”gone viral” was a frightening expression. It meant the rapid spread of disease and death. You know. Like a virus.
Now, of course, it means that something has really caught the attention of a great many people over Twitter, Facebook and other pipes of the internet. That it is being shared from one person to another, one circle of friends to another, picked up over and over in a way that no one did, or could have, planned.
It might be good or bad, or it might be seen as good by people of one political or social group and bad by another.