Why platforms had to cut off Trump and Parler

Last week saw unprecedented mob violence in our nation’s capital and a huge shift in the internet’s relationship with President Donald Trump. Major sites like Facebook and Twitter, which excused harassment and outright threats from the president for years, banned him in a matter of days. The social network Parler, a home for Trump supporters too extreme for those big networks, was banned from Apple and Google’s App Stores and then by Amazon’s hosting services. As of this morning, the network cannot be accessed in any way.

Skeptics have called...