[csense]

Anonymous or pseudonymous publishing is an essential element of Constitutionally protected freedom of speech [1]. If the government knows who's posting what, it's a lot easier for them to harass, intimidate, punish, or otherwise suppress people who post uncomfortable or politically inconvenient things.

Recent New York Times headline: "Homeland Security Wants Social Media Sites to Expose Anti-ICE Accounts". I'm sure the administration would be very happy if there was a database of government issued photo ID's for every account on Facebook. And if the government gets the ID's of those accounts, I'm quite sure nothing good will come of it for either the individuals involved, or the ability of the people to understand whether the government department in question is going about its duties in a way that respects the law and the Constitution.

[1] My username refers to an anonymously published pamphlet that played a key role in US history.