There’s an advertising campaign at the moment opposing cruel treatment of pigs, the web site is at http://www.savebabe.com/ . They have rented advertising space at train stations to publish the URL.
One thing that they don’t mention is the health issues related to factory farming. It makes sense to concentrate on one message at a time and they are concentrating on animal cruelty. But probably more people will be concerned with the risks of disease, parasites, and anti-biotic resistant bacteria present in meat produced from the factory farms.
Also wild boar tastes better!