You may have noticed people tweeting things like, "#13: I've always had a crush on u ;)" yesterday and wondered what the heck was going on. Initially it looks like there's some kind of secret code like the breast cancer awareness meme, but it turns out the numbers are being used instead of people's names as part of a game that was trending on Twitter all day Tuesday.

The premise is pretty simple: Person A tweets a request for people to direct message them with a random number (like "inbox me some numbers"), Person B responds with a number (let's say #4 for kicks), and then Person A tweets about Person B, starting the tweet with "#4" so Person B knows it's directed at them. The idea is that you can tell people what you really think of them without fear of embarrassment.

So instead of tweeting, "Debbie, you're a horrible kisser," you can say, "#52: You're a horrible kisser" and only Debbie will know it's her. Fun and no one ever gets hurt! (Except Debbie.)

With the game's popularity on Twitter, it's inevitably spread to Facebook (or from Facebook? We're not sure) with a few slight modifications.

First, a person posts a status proclaiming that they are playing The Number Game and asking people to "inbox" them a number:

Next, the person's friends send them private messages containing numbers. These numbers are in turn used in the original poster's response, where they lay it all on the line and share their opinion of the person:

For the most part it looks like people are being kind to each other -- lots of "LOL GUD TYMES" and "we haven't talked in forever, girl!" -- but even if you end up with a negative peer review, you're anonymous, so there's virtually no risk of public humiliation.

This meme was pretty much made for social networking sites because, let's face it, we love hearing about ourselves, but I bet it's shortlived. People are only going to tolerate so much news feed spam before they get annoyed with reading what Frank thinks of #21's car or how much Jessica wishes she'd never broken up with #2.

Enjoy it while it lasts.