One of the exceptions to freedom of speech is falsely shouting fire in a crowded theater. (Actually, the case in which Justice Holmes used this term may have been overturned or, as the lawyers say, distinguished.)
“Facebook Cracks Down on Vaccine Misinformation,” The Wall Street Journal, March 8, 2019. Even though not a government entity (yet, anyway), Facebook attempts to stop the spread of (what Facebook thinks is false) information about vaccinations.
By exercising any control over the content on the Facebook platform, does Facebook take on some additional obligations? It’s no longer merely a platform; is it a publisher?