Courts are entitled to reasonable cooperation from third parties to facilitate the administration of justice. Turning over documents, showing up for third-party depositions, testifying in front of a grand jury, drilling into a safe deposit box, etc. In Anglo-American law, that idea predates even the Constitution.<p>But at some point, cooperation goes beyond reasonable into the area of &quot;unreasonable burden.&quot; As a practical matter, the test tends to be one of economics. How much does it <i>cost</i> to comply, and is that cost a reasonable one given the party being compelled?