Google, Facebook and Apple don't need a warrant because you voluntarily sign up to give them all your information. If you emailed the police every time you drove somewhere, I don't think they would need a warrant to read those emails.

As a general point, the Bill of Rights isn't an enumeration of rights per se. You don't have the right not to be searched. The Bill of Rights are a limitation of the exercise of federal (and through the 14th amendment, state) power. So no, Facebook could send someone to install a GPS device on your car and it wouldn't violate your 4th amendment rights, since Facebook is not the government. It would, however, probably be a simple trespass for which they could be sued in state court.