The basis for Warrant Canary is that people publish an &quot;everything&#x27;s ok&quot; message periodically on their project or website, so if the feds pressure them into creating a backdoor (as was suspected in the untimely death of TrueCrypt), they simply stop posting the &quot;everything&#x27;s ok&quot; message. The untested legal theory is that the government can compel you to remain silent about proceedings via gag order, but they cannot  compel you to state anything falsely. If apple pleads the 5th, it may set a precedent that&#x27;s relevant to Warrant Canary cases.