The point is not about superseding the law. The point is that if your company privacy policy says "we will not divulge this data to 3rd parties under any circumstance", and later they are served with a warrant to divulge that data to the government, two things are true:

- They are legally obligated to divulge that data to the government

- Once they do so, they are civilly liable for breach of contract, as they have committed to never divulging this data. This may trigger additional breaches of contract, as others may have not had the right to share data with a company that can share it with third parties