But as for the slowly becoming brutal and unethical? Nah. They've done that for a while. A recent example of this is the Cold War: they fed radioactive oatmeal to mentally-retarded to children to "test its effects" (http://tech.mit.edu/V114/N28/fernald.28n.html), supported brutal tinpot South American dictators to "fight communism" (http://www2.gwu.edu/~nsarchiv/news/20000919/) and abused this giant list of people who we thought were Communist (http://en.wikipedia.org/wiki/House_Un-American_Activities_Co...).
Notice how the actions and methodology are the same (replace "communist" with "terrorist"). Notice how the reasoning is the exact same. Notice how it all starts with "wanting to protect you" from a threat most feel is real, and does exist to some extent.
The people in the government are humans like anyone else. Some people really can't grasp the idea that those people might actually be abusing you or lying to you. If and when they figure it out, they have a small revolution, become heroes, write a book, and then forget about the past and the victims and keep on rolling.
Maybe if we'd all stop have "reasonable" discussions about how people who say, "HEY GUYS, THIS PATRIOT ACT THING IS A REALLY BAD IDEA" are crackpots or paranoid when it's happening, we'd have more of a chance of stopping this...but probably not.
Systems run by people are created and exist to protect us from the nature of people.