The Content Management section allows you to manage approval settings, playback options and public access for many videos at once.
Click the cloud icon in the sidebar to access the area. You can use the Categories filter, Content age filter and search box to narrow down your list of videos from everything to just one category, or even search by username.
Use the checkboxes on the left hand side to select the videos you want to manage. Then select your action from the dropdown and click Apply to save you changes.