In the brouhaha over Eduardo Saverin's renunciation of American citizenship and the subsequent attempt by some U.S. politicians to make political hay out of it, allow me to introduce one who has clearly given this matter some thought.
Ron Paul is a Republican Senator from the state of Texas. A medical doctor by profession, he is a conservative and some folks refer to him as a libertarian. I am an admirer not because I support everything on his platform and not because I consider myself a conservative.
I like Ron Paul because he says what he thinks and sticks to his principles of "limited constitutional government, low taxes, free markets, and a return to sound monetary policies based on commodity-backed currency." He is in the race for president. He will not win but he's great to watch and worth listening to. He released this piece recently (hat tip to Just Me for the link) about Casey and Schumer's ex-Patriot Act. It's a sober and cogent analysis of why this is a very bad idea. Either he or someone on his staff took the time to examine the proposed law and seriously consider the potential untended consequences. He actually noted the impact this Act and laws already on the books like FATCA (destined in theory for the rich) would have on regular folks like retirees. He then took all that information and decided that, no, this just isn't right and said so out loud and in plain English.
Have a listen. Made me feel a bit better about the American political process and perhaps it will have the same effect on you.