Anything you say on Facebook, Twitter, Google+, LinkedIn, Foursquare, etc, is evidence that can be presented in a divorce or a custody trial or a support hearing. As the article notes, one is hard pressed to argue that they can't afford child support when the evidence shows they are checking in to expensive restaurants multiple times a week.
Another good piece of advice in this article, and something again I've blogged about, is to change your passwords. You should change all passwords and keep the passwords separate and hidden. This will assert that you want these accounts to be private, and if you do not share your passwords with your spouse, pursuant to recent Michigan caselaw, you are asserting that those accounts are private and your spouse does not have access to them.