ability to delete all unused library media at once

When there are a ton of items in the library, there's a good chance that some or many are not being used on the timeline. It would be nice to be able to clear these from the library in one click. In the meantime, the process is manual-- individually select the media and delete. If your clip's not on the timeline, it will disappear. If your clip's on the timeline, you'll be prompted to confirm the deletion. I could see how a "delete all unused media" feature might be potentially dangerous, but it would be nice to have.