We need to look at websites as service providers/data carriers akin to telcos. The government has issued a slew of regulations to prevent artificially strong network lock-in with telcos, mandating wireless number portability and certain levels of device compatibility.
We need to recognize that Facebook is not a content creator as such, but a neutral carrier who transmits the data generated by its users, and that the users need their freedom and mobility to be respected if we're going to have a free and competitive market in cyberspace. There is no good reason that Facebook or Google should have such excessive unnatural ownership and access blockage rights.
n.b.: I say this as someone who is very conservative politically. Intellectual property is a government-granted monopoly that we have let run far afield.
I don't resent property ownership in the slightest, nor do I resent profit-making. I do resent an oligopoly exploiting regulatory capture and public technical ignorance (cf. Clarke's Law) to pass laws that allow them to arbitrarily and brutally crush innovative and competitive entrepreneurs.
The government has given Facebook offensive weapons against competitors. They either need to respond by giving the consumer defensive weapons against corporations whose zeal for intellectual property seeks to block or subsume the consumer's access to the marketplace, or they need to remove their interference all together.