title: How to download video ads from Youtube?
body: <p>I'd like to download some (I mean a lot of) video ads from YouTube (not the videos, but the ads that are played before them) for research purposes. </p>
  
  <p>Any suggestions for tools or ways this can be achieved? I won't mind some programming on my hack but I currently have no idea how. Also, YouTube is not an requirement; video ads from other video sites work for me too.</p>