SEOUL, South Korea — A government critic who called the president a curse word on his Twitter account found it blocked. An activist whose Twitter posting likened officials to pirates for approving a controversial naval base was accused by the navy of criminal defamation. And a judge who wrote that the president (“His Highness”) was out to “screw” Internet users who challenged his authority was fired in what was widely seen as retaliation.

It feels like the Internet is a massive human experiment playing out all over the world in real time.