Immie, I hate to say this, but you are naive as hell if you think the FBI hasn't always had the authority to send the men in dark sunglasses to your house and take you into custody. If the US Government sees you as a potential threat to national security, you can bet your sweet ass, they will come get you. Now, I don't know when this all started, but I know it's been around since the days of FDR and WWII, perhaps longer. During the Civil War, Abe Lincoln suspended Habius Corpus! (You do know what that means, right?)
So the silly notion that our laws somehow "protect" us from the government, are laughable. Now, you go on to spout some bullshit about "oppressive government" and I challenge you to show me one American citizen who has been "oppressed" by Bush policies! It's overblown hyper-reactive bullshit, and I am calling you on it!
Let's have an analogy here, for old times sake... Say you are the manager/owner of a nice upscale condo in a well-to-do area... your tenants are very wealthy and pay you a nice sum of money to provide them a well-secured living environment. You get a phone call one day, your security gates have been breached by several thugs, they've already broken into one condo, but your security guys have no idea where they are now. You do know they are inside the premises. What is your course of action? Go ahead, Mr. Genius... tell me what the hell you would do under those circumstances? Your tenants have rights to privacy, you can't go breaking into their condo's looking for these guys without their permission. So, what can you do???
For the sake of this analogy, we have to assume there is no police to call, it's entirely up to you to rid the condo of the thugs and restore peaceful security to your tenants as soon as possible. Now let's add another tid bit... you learn that the thugs have master keys, and can access any condo at will. So, do you wait until they strike again, and hope you catch them in the act? Or would it perhaps be reasonable to let your tenants know the problem, and ask for their cooperation in helping apprehend the thugs? Wouldn't it be for the "greater good" if you had to go into someone's condo to find the thugs?
Immie, it is much the same with regard to the terrorists, they are here, they are living among us, and they are using our freedoms and liberties to enable more attacks like 9/11. Now we can stick a cob up our ass and act like it's outrageous that government is allowed to violate our rights, but without those specific measures, there is really no practical solution to the problem. We simply can't apprehend thugs who don't play by the book, by playing by the book... and it doesn't matter how outraged you are about that.