Raise your hand if you made a mistake this weekend. Maybe sent a scathing Facebook message to an ex who broke your heart? Told everyone — via Twitter — how much you hate your boss? Uploaded something scandalous to YouTube? Well, it's too bad we waited until Sunday afternoon to tell you about the Social Media Sobriety Test, now isn't it?

This week, web security company Webroot released a new Firefox plugin called "The Social Media Sobriety Test" with the tagline, "Nothing good happens online after 1 a.m."

The deal is simple, download the plugin and customize the settings for a variety of social media sites — from Facebook to MySpace to Tumblr (for the bloggers among us) to e-mail accounts like Gmail or Hotmail.

Set your hours of intoxication, and if you try to sign on to one of those sites during those times, you'll be asked to pass a test. I tried it out — about five minutes ago and fully sober — and failed said test, however. You try typing the alphabet backwards. It's not as easy as it looks.

We would like to say that a tool such as this is merely a fun diversion, but judging from the neverending supply of material on Texts From Last Night, it's probably rather necessary.

NB: This plugin doesn't work on mobile devices, which means that when one is out and about — Android or iPhone in hand — one's only protection is one's own common sense. Good luck with that.

Update: The plugin is also compatible with Internet Explorer, Chrome and Safari.

Photo courtesy of Flickr, Egan Snow