From my point of view, its not just about whether the company is private but also how easy it is to substitute the service. Twitter and Facebook are not close to the only means of publishing information. I don't think that people deserve any particular audience for their speech, so the ability to substitute other publishing methods alleviates concerns about censorship on my part.
On the other hand, its much more difficult to switch ISPs, so I would be very concerned about censorship at that level. Things like search engines which are substitute-able but held by few hands and difficult to replicate privately are more of a grey area in my opinion.
On the other hand, its much more difficult to switch ISPs, so I would be very concerned about censorship at that level. Things like search engines which are substitute-able but held by few hands and difficult to replicate privately are more of a grey area in my opinion.