A checkbox is needed next to users and streams so you can edit/delete in bulk. For instance when new channels are added you have to currently go through each user individually adding the streams. With a checkbox system you can select all on that page and add the new streams in one for all of them.
User deletion if you have a bank of users on a page to delete you have to delete individually. A checkbox with select all and you don't need need to you can do a page in one go.