The Meatrix

I'm not sure how I missed this animation; apparently, it's the most popular online advocacy film ever made. It's a pretty good overview of the major problems with factory farming, particularly the ones that affect human communities.

Just so you know, this is not vegan propaganda; it's anti-factory farming propaganda that suggests less dangerous and destructive sources for meat products. I mention it here mainly because it ends with a link to a zipcode-based search engine for family farms in your area. That's a great resource, IMO.