Without any real testing: The information, if MSF shall show some/all of those banners is most likely in the cookies - which are at your personal computer/device within the browser. If the information is lost (i.e. settings in browser), MSF has to revert to default settings - which is showing ALL banners again.

As I said - no testing, no investigation - but that is the "most feasable" and economical way to implement it. And yes - I can be grossly wrong!