That video is so loaded it's kind of ridiculous. Not that it's not true or anything, but it makes things seem much worse than they really are, especially in comparisons to what animals would be like if left in the wild.
Really though, all I have to say is, it pays to be at the forefront of evolution :) You think if those chickens were in our position they'd care about you? Hell no! So.. take that chickens!!
Seriously though, if you compare the suffering caused by this type of thing to the suffering caused in the wild you'd be hard pressed to call this unethical. Now sure, this video isolates some really bad incidents, however, in general, the lives of animals who suffer (and yes, they do suffer, I won't argue that) in these situations are comprable to animals who suffer in the wild. Go watch some animals in the wild and you'll see for yourself. And I don't mean those nature shows either.
What do you think happens when an animal gets sick in the wild? Since there's a lack of evil antibiotics, many suffer for weeks or months, and then die. Other animals get injured, their injuries get infected to hell and back, causing them to be in serious pain for many months, not just the "6 hours" like the video complains about some of those chickens. After that, of course, they die. Instead of reading just what PETA has to say I suggest you check out both sides of the argument. I used to work as a trainer in the Atlanta Zoo and before doing that I had to learn a bit on animal ethics, so I'll tell you that in general animals in the wild don't have it much better (if at all) than the animals in those farms.
Of course, another point to consider is HUMAN suffering. Why does PETA and vegetarians only care about fucking cows and chickens and shit, when humans are caused to suffer by what they propose. For example, let's say we treat those "oh so poor chickens" better than we do. This increases costs for farmers. Supply and demand dictate that this increases cost of buying these foods, and now, poor timmy, who comes from a moderately poor family, can't afford to buy meat. So what does he do? Well he buys veggies to eat! Great, now he's healthier, but since all the timmys have to do that, it sends demand for veggies up, causing them to also increase in price. So joey from an even poorer family than timmy can no longer eat anything! Yay! So now instead of chickens starving we have people starving... And when I give this example, I don't mean for you to just think about the U.S. Think about those countries where many people can't afford to eat at all and starve to death. By improving the life quality of farm chickens, you've just condemned a larger number of those humans to starvation. Now this might be self-interest talking, but I think humans suffering is far worse than chickens suffering. We're better than god damned chickens. If we weren't, we'd be the ones being farmed. So while some people might like to sacrifice the wellbeing of people so that chickens can have better lives, I really don't want to do that, so I say, if it makes food cheaper and therefore allows for the feeding poorer populations, let the chickens suffer!
I know PETA wants to make it seem that all of the money saved by making chickens suffer is padding the pockets of some rich guy who is laughing maniacally from the throne of his evil chicken-hating empire, but simple supply and demand dictate that this is not the case, much to PETA and friends' chagrin.
/rant off :P