The court rulings that turn on whether the platform owner exercises editorial control are wrong, and legislation should fix them. The real question should be whether the platform operator has reason to know what is in the communication.

The USPS doesn't know what is in libelous mail. Neither does FedEx or UPS. None of these entities are publishers. But Twitter knows and Facebook knows. Indeed, their revenue models depend on knowing what's in the message, because that's how it figures out what ads to send to whom.

Any platform that provides message services in exchange for access to the sender, the message, and the readers, should be regarded as a publisher and treated accordingly. Times v. Sullivan should set the liability standard.

In contrast, a platform that charges users for sending or receiving messages, but does not collect (or sell!) any data about what is sent is analogous to a mail service and should be immune to suit. The mail service should, however, be obligated to identify the sender of defamatory or illegal material. The law has no reason to enable anonymous torts and crimes and every reason to regard anonymity providers as co-conspirators.