It's not just about keeping us safe. It's about keeping the power. This government was created on the basis that the people have the power. When we give more power to the government, it is upsetting the balance necessary to keep the government a productive government, a good government. When we give them power, we are risking our ability to keep our freedoms. We have the right to not be searched without justification, and the Patriot Act pretty much contradicts that right. How do we know that in 5, 10, 15 years that more of these rights wont be taken away under the justification that "it's for the greater good of national security"
The government has ways of keeping America safe without have to snoop through innocent people's lives. I have nothing to hide, but I don't want government to spy on me without having to give any notification that they are. It's like having a peeping tom.