May I make a modest proposal? 10 backyard chickens presents a smaller threat of rampaging infection than 1,000,000 chickens housed in a single structure.
These people with only a few birds are less likely to take the time and money to responsibly deal with a potential outbreak in their flocks. Some will, but many won't, and the ones who don't then become a vector for spreading the disease even further, including an increase in the possibility of the virus making the jump to humans.
To be clear the solution isn't to discourage people from keeping chickens in their backyard. The solution is more education on the issues and regulations to require people to keep their flocks responsibly.
But we live in America, where apparently it's an individuals' right to put their whole community at risk. So, I don't know what else to say other than that ignorance kills.
Good. The chickens are surely experiencing richer and longer lives that way. Locally-sourced food is good for everyone, and the proximity to the live animals has the potential to foster empathy. I hope that many people make their own mini farms and share with their neighbors, and that a sense of community grows.
I hope people plan to keep them indoors otherwise they will just catch it from a passing sparrow or other animals that have been shown to carry it, like cats. Once it jumps to dogs we're all fucked because dogs like to chase birds and dogs live in very close proximity to humans.
Done correctly they are less likely to get it. I think people becoming more resilient and raising chickens on their own is a good thing, even though it slightly increases avian flu risk.