Nobody sane would, intentionally. But I&#x27;d bet the house on it happening by accident quite a bit.<p>At a technical level, I like this idea. When used well, it makes sense to allow. It&#x27;s hard to fault it without bringing in human error, politics, or economics.<p>At a practical level...<p>I can&#x27;t wait to see what happens when a bug allows Facebook to serve this header on all pages, even for a few minutes. The most Facebook dependant folks around, those checking their phones every five minutes, will be stuck in a perpetual time freeze, unable to move forward ;).<p>I also can&#x27;t wait to see what happens when a government tries to ban a cache-control: immutable page.<p>Or even what happens when, someday, Google is selling it&#x27;s assets and gets to &quot;google.com.&quot;. (Someday, itll happen - Google won&#x27;t exist for all eternity)