This being the case for me too.
"I don't know if I want to read a 620-page"
I didn't, but I did read around 100 pages and in those pages is the answer that these people who are censoring the American people are not private. So all of the questions "do you have the right as a private concern" is really moot, even though I agree with most of your assertions regarding rights of ownership.
"Also, user agreements are contract law and contract law is enforceable."
So is the constitution a contract and if your doing business on the land your subject to it's law by agreement of doing that business. The fact that by virtue of you being on the land you are also a beneficiary is icing for all businesses. The fact that the Agencies are censoring the American Public against that contract is what We The People should be concerned with. Private business is not the concern here.
"There would be a lot less bullshit if everyone were doing everything voluntarily."
I agree with the above statement and will take it one further. There would be a lot less bullshit if people would stop thinking that there is such a thing as authority over us. There is only one law everyone is bound too. "Harm No One". If people would simply hold the living beings accountable to that one law regardless of the costume they are wearing life on Earth would resemble more like existence in heaven.
I also agree that the protest is best expressed by not supporting the Corporations that are creating the contract bullshit. In fact right now more than 60 % of corporations are in contract with the US Federal Government making them employee's of the Federal Government on the sly. Thus they to are not private and must follow the constitution in there practices.
You could look up grants that funded Corporations like Facebook, YouTube, Twitter and Instagram and many other social media and realize by that alone they are not private, but Government Agencies on the sly. Which is the point the PDF would answer for you and is why I shared it.
Thanks for your comment!