When you're having arguments with know-it-alls on the internet
"What's your favorite novel?"
"Atlas Shrugged. It's a masterpiece."
"Oh. What is it about?"
In the current condition that we live in...
When someone makes a joke / pun that is so bad, it's simply unforgivable.
That must have happened at least once to each of you on internet forums.
When your friends have neither culture not good taste in anything.