You are communicating with your friend, but instead of talking directly, you write a note, hand it to Mr. Facebook, who opens it, reads it, then closes it and hands it to your friend, who in turn writes back, handing it to Mr. Facebook first. That’s more how communication happens on FB. FB acts as the mediator of the communication, a middle man whom both of you interact with to have the conversation. They are not spying from afar—you are directly giving them your communications.
If you write something on your note, which Mr. Facebook doesn't like he takes the liberty to alter the note before handing it to your friend.
If I write “A” is it possible that “B” arrives?
Or are you talking about censorship, so if “A” is unlawful, then it does not arrive at all?
[1] https://www.google.com/search?q=facebook+censoring+messages
[2] https://linustechtips.com/topic/912936-facebook-private-chat...
You come to a restaurant to eat dinner with your friend, who arrived early. Unbeknownst to you, your friend arranged for one of their acquaintances, who owns a business, to observe and document your arrival, from a concealed location, behind a sign for that business.
What's relevant in this case should be that a reasonable person, upon observing a Facebook "Like" button on a page, comes to the conclusion that "that button exists for me to interact with, and interact with Facebook, related to this business."
More specifically, a reasonable person would not come to the conclusion that a Facebook "Like" button allows Facebook to load arbitrary code into your session with the business, the purpose of which is to track you and compile information on you.
It's unreasonable to expect people to choose to opt out of what they don't even understand.