A possible Use Case for a Filter could be the Choice to show all Events created by a certain User.
Whenever that User creates a new Event or changes an old one, the Result of the Filter is automatically updated.
Most people in Europe would associate "Boko Haram" with the entire continent Africa.
As seen here, in fact they are focussed on Northern Nigeria.
"Boko Haram" (News)
All Articles which have something about an elefant in the topic.