Select None makes no sense. Who would want to see in their log nothing at all???
We include a 'Show All' because we establish a user might want to quickly (re)enable showing all (or, clearing the filters). ... [EDIT]On a second thought. Screw it. Such stuff should be indexed by Tracker. Tracker indexes IM logs, documents, images. Why not voice logs? Why that seperate treatment? Might as well make tons of exceptions while purpose is to include backends for Tracker making it more useful. Hence differentiation makes no sense. This also allows easier to search on communication based on other metadata, allowing more fine grained filtering instead of only outcome_of_used_protocol. Such as: Person, Group context (Work, Family, etc). Also allows data of voice to be combined in search with other protocols such as IM or SMS.[/EDIT]