I was pleased to see a recent PETA campaign advocating for the use of controlled atmosphere killing of poultry. Rather than their typical sensationalist approach (ex. http://www.peta.org/features/would-you-eat-a-chickens-period...) that appeal only to the faithful. They made economic arguments:

Typical slaughterhouse practices are stressful for workers and lead to damaged product.

Improving worker conditions decreases employee turn over and boosts yield.

It's probably wishful thinking to take this as a signal they're transitioning to become a serious advocacy organization.