That Facebook in general isn’t the best choice, when trying to maintain a certain degree of privacy, is almost common sense. However, before posting something on Facebook it’s always a good idea to think twice whether you want this information to be associated with your name.
So when writing something in a post or chat field you might sometimes decide not to actually post it. Facebook though seems rather interested in what you have intentionally chosen not to share. They call it “self censorship” and two Facebookers have now published a study about this. The article closes with the following:
… we have arrived at a better understanding of how and where self-censorship manifests on social media; next, we will need to better understand what and why.
For the future it may be helpful to keep in mind, that the technology to save your unpublished content already exists. It is basically the same how Google offers search suggestions while you are typing in the search box.