title: How to "invalidate" portions of ASP.NET MVC output cache?
body: <p>Is there a way to programmatically invalidate portions of the ASP.NET MVC output cache?  What I would like to be able to do is, if a user posts data that changes what would be returned from a cached action, be able to invalidate that cached data.</p>
  
  <p>Is this even possible?</p>