The same logic that will lead you to choose "cached" – application cache level and not per user – will lead you to the need to clear the cache for all your users."… I can't envision that many possible uses where you'd want to clear the cache for all the users of your system."
This is a very good point one should consider when coming to decide which level of caching to use, and when actually setting it." Setting the cache to be not "By User" i.e. system wide cache is a little risky for, say, dynamic report regions where the report query is customized for each user based on his authorization level, search filters, etc"