Free Speech?

So the Dolphins have *suspended* Don Jones for his negative tweet about Michael Sam, and I cry foul. I'll skip the "what ever happened to free speech?" malarky, as the First Amendment protects free speech from the government, not private entities. But it wasn't like his tweet was full of fire and brimstone, or even that noteworthy, and at some point people should be free to disagree without the expression of that opinion endangering their paycheck. The Thought Police grow ever more powerful.