Boy, you people are dense. I'll again attempt to explain it to you in very simple terms:
Humans have introduced non-native cats into the environment.
Some cats are domesticated, some are feral.
Feral cats are descended from domesticated cats.
Both types of cats are non-native.
Cats are allowed to roam free, which is a behavior permitted by humans.
Free-roaming cats, whether domesticated or feral, like to hunt.
Both kill or injure countless native wildlife due to non-native cat predation.
Some species of native wildlife have gone extinct.
Once again: Humans have introduced cats into the environment, therefore human behavior = cause of extinction. (You've seemed to have comprehended my point, Aurelius141... good for you!)
BUT! Because they're cats and everyone just loves cats, we will allow the continuation of predation and extinction of countless more species of native wildlife. Yes, there will be nothing done to address this problem. Why? Because crazy whacked-out cat owners don't think it's a problem.
@Jessdickenya: I'm not used to doing people's homework for them, but you seem to need some much needed help in learning how the internet works: http://www.nature.com/article-assets/npg…