Ability to tag search over all blogs we follow

With the browse by tag feature, I had expected there to be an option to click that'd allow it to browse by tag within the blogs that we already follow rather than browsing all blogs. 
I believe it should be some what easy to implement since the default browse page is displaying the blogs that we follow. It would just be using the by browse by tag function on a subset of blogs that an account already has defined, rather than on full set of all blogs.