Your definition removes all distinction between the concept of a protocol, and the concept of an API. Google Calendar doesn't implement the Google Calendar Prot

Your definition removes all distinction between the concept of a protocol, and the concept of an API. Google Calendar doesn't implement the Google Calendar Protocol, there is no standards body involved in determining how Google Calendar works, you're not free to go an implement your own Google Calendar compatible service, and Google can change Google Calendar without consultation with anybody. There is no definition of protocol where a single-service API, designed, implemented and published by a single party is a protocol. Google Calendar implements an API. If your argument is that companies should be compelled to publish good API documentation, and allow any client to connect to them, then aside from creating a completely unnecessary system of regulatory moats, and aside from using the wrong words to describe this idea, you're likely to run directly into a 1A violation.