Original quote from US Bill of Rights: "Congress shall make no law ... abridging the freedom of speech, or of the press..."
Government must not interfere with free speech in any form, as long as it does not violate NAP - whether spoken, written, printed, transmitted, programmed, drawn, filmed, recorded, televised, or processed or communicated any other way, and whether it's audio, video, electronic, data, or any particular medium or format. It doesn't matter whether someone thinks the content is offensive, politically dangerous, pornographic, or anything else.
This right is also presumed against individuals and organizations except to the extent otherwise agreed, i.e. it's a contractual matter.