As often as Facebook likes to push video ads, they've been relatively easy to ignore. The sound is usually off until you click, so you can scroll by to whatever you really meant to look at. However, it might be tough to completely gloss over them in the near future -- Facebook is rolling out a tool that automatically captions video ads. Whether or not they appear is up to the advertiser, but the hope is that you'll stop (if ever so briefly) to read what a promo is saying instead of skipping to the next post.