Second, I highlighted all manners where freedom of speech is protected; in the case of Meecham, (1) any individual could take him to court if this had happened in the US and won since freedom of speech does not extend to disputes between individuals or businesses, only when one side of the litigation is the state of the federal government. (2) if Meecham was in America and not in Scotland, he wouldn't have been taken to court by the procurator fiscal since this is a peculiarity in Sctoland's legal system where all prosecutions go through that legal process and not some extraordinary event where the government limited someone's freedom of speech.
Also, the US government imposes three very specific parameters that would make Meecham's actions viable for prosecution. (1) Time, place and manner restrictions, (2) the related public forum doctrine and (3) private actors and content of speech. Shall we see them one by one? Good.
(1) As you can see by this
case [or
this, or
this], limitations have been imposed on the manner, time and place where americans can exercise their freedom of speech. Restrictions are always valid provided that they are "justified without reference to the content of the regulated speech, that they are narrowly tailored to serve a significant governmental interest, and that they leave open ample alternative channels for communication of the information". You can see another case here where limitations on freedom of speech were imposed by the Supreme Court. It's also interesting that the Supreme Court always intervenes when one side of the litigation is the state apparatus.
(2) The related public forum doctrine means that you can't go about and 'free speech' wherever you like; I quote