Yeah whatever you say on your post is not considered a legal communication. The statements you post on your wall are akin to randomly shouting out statements on the street. Other parties are not expected to listening to that and taking that seriously (FB included).

It's like leaving an email in your drafts folder expecting google to read it. Or typing something into Google Search box and expecting that to be legal communication.

More info: https://www.youtube.com/watch?v=xDHDM7PfyYs

The above video makes good points even though it's been posted by college humor (not particularly meant to get your legal advice from)