Correct! Your company can fire you for saying something bad about it online, but they can't throw you in jail. No one can throw you in jail for what you say online (with technical exceptions for some forms of hate speech I believe). Companies can't do it, nor can the government. Why? Because of... heh, The Government!

You've got press blackouts in the 1940s, you have the PMRC triggering congressional hearings about musical content in the 80s, you've got crypto laws in the 90s, you've got the DMCA, you've got the DHS seizing domains, you've got calls to have Wikileaks banned. Your all-caps "the government" did these

Yes. Sometimes the government violates its own laws. And when it gets caught doing that, other parts of.. The Government, actually spring into action. This is called the system of Checks and Balances, and you may have heard of organizations such as the ACLU and the EFF making use of it to correct the Government's behavior using... The Government.

The internet, as a whole, belongs to no one. It belongs to us all. In a sense, it is Public Property (on the whole). Protecting it is therefore the responsibility of The People, through the mechanism known as Government.

(Edit: BTW, you'll note that most of the examples you cited happen to be caused by contamination in The Government caused by the private sector, known as regulatory capture (as another commenter pointed out).)