Relevant case law has revolved around the Fifth Amendment privilege against self-incrimination.

FORBES: The General, The Biographer, And Unencrypted Email

Even though they have not advised you of your rights, you can still exercise your Fifth Amendment privilege against self-incrimination.

FORBES: What Should You Do If You Get Pulled over for Drunk Driving in California?

You try to quash the subpoena based on your Constitutional privilege against self-incrimination, since handing over the records clearly would incriminate you.

FORBES: IRS Can Make You Produce Offshore Bank Records Even If Self-Incriminating