Unless you shoot your videos in controlled environment like a movie set, you often end up with a video with unwanted, unintentional elements like documents with sensitive information(ID cards, legal documents, documents with addresses, etc) or just people who don't want to be included in the final video.

If those "unwanted, unintentional elements" are still, it is easy for any novice editor to blur them out. But I can track fast moving elements and blur them for you.