Personally, I use DestroyTwitter 95% of the time. (with web and HootSuite being the remainder)

That could probably cause quite a few problems for webmasters, especially if Yahoo aren't deactivating overuse. I've never used BOSS before but I think Yahoo should at least make it possible for webmasters to stop Yahoo from providing information if their query count is > 9.5K or at least notify them when they are this point.