This line of thought always reminds me of Marsh v. Alabama: https://en.wikipedia.org/wiki/Marsh_v._Alabama

> a state trespassing statute could not be used to prevent the distribution of religious materials on a town's sidewalk even though the sidewalk was part of a privately-owned company town

Are we at that point of broad-spectrum BigCo dominance yet? I'd say probably not, but sometimes it just seems like a matter of time.