Does social media like Facebook or Youtube count as publishing?
Yes.
The answer there is long and complex.
Short version: Does the subject have an expectation of privacy, and does it fall under journalistic rules.
There are also some laws covering national secrets, courts, and so on.
But, a cop in plain view on a public street performing their job, or any other actions is photographable and filmable. You can publish it as news. In the end, a court will decide that.
Oh wow, so you just don't know until AFTER you are sued. That is messed up.