No, your speech is still safe even if Comcast cuts off your service. The internet does not equal freedom of speech. Just because the barrier of entry to Twitter

No, your speech is still safe even if Comcast cuts off your service. The internet does not equal freedom of speech. Just because the barrier of entry to Twitter or Facebook is considerably easier than appearing on CNN they are companies that can have rules regarding who they allow on. If people are being arrested for what they are saying then that's censorship and something to be worried about.