No, because that's a private company. Your first amendment right to the freedom of speech is freedom from government center ship and interference in your speech

No, because that's a private company. Your first amendment right to the freedom of speech is freedom from government center ship and interference in your speech. It does not apply to private companies. Now with that said, adding a footer, I don't think would be a problem, but if you set an away message and they changed that for a political reason, then it could be said that they impersonating you to broadcast a political message. Then it might be a civil matter.