Most of the Founders published under pseudonyms, even after the Revolution. Hamilton, Madison, Jay, Franklin - all had pseudonyms for their political writings. The Federalist papers were signed "Publius". What Franklin did was in no way unusual for that group.
In the US, anonymous speech is considered a core part of free expression, and is treated as a First Amendment right. That's a US perspective, stemming from US history. EU rights as to anonymous speech are weaker, and UK rights are weaker still. China has no right to anonymous speech at all.
In the US, anonymous speech is considered a core part of free expression, and is treated as a First Amendment right. That's a US perspective, stemming from US history. EU rights as to anonymous speech are weaker, and UK rights are weaker still. China has no right to anonymous speech at all.