'Late Night'/Screenshot by Chris Matyszczyk/CNET

You know that something's caught on once Facebook tries to copy it.

So you know, hashtags are a very big deal.

Everyone's creating them. Though it's not entirely clear why they're creating them. Is it to summarize something they've just said? Is it in the hope that someone else will admire the hashtag so much that they'll use it in their own tweets?

Jimmy Fallon and Justin Timberlake think it's all gone too far. It's #notbringingsexyback.

So on "Late Night with Jimmy Fallon," Fallon and Timberlake attempted a conversation with hashtags being spoken out loud.

#Fallononthefloorlaughing.

When you hear what is normally written, it sounds so very much like two very young children trying to outdo each other at a silly game.

This silly game, though, seems to have invaded every possible social network. Some people cannot write a status update or a tweet without some form of hashtaggery.

If it isn't a simple #LOL, it's a self-explanatory #ExecuTips, #Kumbaya, or #AngelaMerkelIsMyFraulein.

Not so long ago, no one pressed the hashtag button on their keyboard.

Many people probably weren't aware that the hashtag was anything more than "the pound sign" that's repeated by every machine that purports to represent customer service.

It took the Root's drummer Questlove, at the end of the skit, to suggest the best remedy to Fallon and Timberlake: "#shutthef***up."

Yet even Questlove isn't immune.

I just innocently wandered to his Twitter account. His latest tweet reads: "Edgar Allen Poe could not WRITE like THIS!!!!!! #CriticalBeatdown."

#wearedoomed.