Yes, although I would say that government control big corporations via regulations.
The big corporations remain big because they play ball with government ideology and policy. Otherwise they are strangled with an arsenal of regulations.
In most cases of surveillance and censorship, the surveillance pressure is exerted by government intelligence agencies upon corporations with the purpose of controlling public perception.
Most companies benefit from having happy, returning customers and goood PR. Surveillance and censorship makes a company less competitive versus a company without it - but only in an environment where government regulations are not discriminating or punishing the company that refuses to play ball with government directives.
All government power is based on public perception. That is why governments makes it a priority to always control the narrative, which requires government schools, regulating companies and social media.