The following quote is from a CNN article about changes in U.S. food safety policy:
"The rules go into effect within a year for producers with more than 50,000 hens, which produce approximately 71 percent of eggs sold to consumers, the FDA's Sundlof said."
Farms of 50,000 hens or more produce 71% of eggs! No wonder the eggs I get from local farmers are so noticeably better than supermarket eggs. Their chickens have to be healthier (since they're not sharing tight quarters with at least 49,999 other hens); the shells of the eggs are significantly harder, the yolks are almost orange, and they taste fresher, with a nicer flavor. A study found that free-range hens produce healthier eggs, with increased nutrients and a healthier fat profile. Smaller operations also don't produce the huge quantities of waste that have caused pollution and contamination problems around the country.
For reference, here's what the Humane Society says about factory-farmed chickens, and further statistics on unsustainable practices in egg-laying hens.