What did Donald Trump do today?

He got challenged in court by one of the few things on the planet he takes seriously: Twitter.

On the day of Trump's inauguration, he found time to ban the entire Interior Department from social media because the National Parks Service retweeted a photo showing lackluster crowds on the National Mall--an enormous sore spot with Trump, as it turned out.

Almost immediately, an "alternative" NPS Twitter account appeared, followed by dozens of other such unsanctioned accounts claiming to represent the employees or supporters of various government agencies. 

According to Reuters, Trump subsequently demanded that Twitter help "unmask" the people behind such accounts that were critical of Trump. Twitter refused on First Amendment grounds, and today revealed that it is suing the Trump administration to quash all such demands. 

Why should anyone care about this?

• Trying to expose the identities of critics of the government is what authoritarians do.

• A president who cannot bear to let mockery or criticism go unpunished is not emotionally fit for the job.