Actually there are some tricks to download any videos from Facebook. It works on any videos on Facebook; your own video, advertisement video, or your friend's video; even when the sharing is limited as long as it is shared with you. Let's check this out:
- You must have IDM installed and it's running on your computer. Just play the video and download button will appear. Click that button :)
- If the download button doesn't appear, try to copy the URL then paste it to http://www.downvids.net/ . The video must be able to download.
- If an error happened (usually because the video sharing is limited, eg. only friends or friends of friends), a text box for Option 2 will appear. You must copy the video page source (in chrome: right click -> view page source) and paste it in the text box that appear in bottom of page. A new tab will be opened automatically, and there is a video. Right click and save the video :)
Hope it works ;)