Looks like it already exists: http://facebookfreefebruary.org/

Ironically, the best way to promote this would be with a viral Facebook status that says “this will be my last post until March, let’s see if I can make it! I challenge Mark, Sarah, Sam to do the same” etc.

I’m amazed at how easily people obey the challenge memes. I’m guessing a lot of them are instigated by Facebook to increase engagement.