Even if the employee sends their social media posts directly to the employer or a potential employer and stores them on their systems? I am interested to read the legislation do you know what states?
https://www.cnet.com/news/six-states-outlaw-employer-snoopin...
Also I read through the text of those laws and they all specifically say that they are not limiting the employers right to monitor their own systems in any way. So Facebook looking up how their employees use Facebook would be completely fine under those laws.