How to report a video:
1. Click on the 'thumbs-down' button.
2. This will give you the option to 'report this video as inappropriate'
3. Now click on 'select a reason' -- which will open a drop down bar of options -- select the option that is right for you and you will notice some options open up again to the right with more options.
4. Lastly click on the 'Flag this video' button -- and you are done!