Sacrifice is definitely one of the costs of freedom. While here in America, it sometimes seems like we have forgotten exactly what we sacrificed to gain our own freedom, there are many examples of other countries fighting for their own.
To maintain freedom is almost as hard as achieving it, I think. Each citizen has to take the responsibility of knowing what is going on in their country or community, and working to keep it free. We have to find ways to solve our problems without giving up freedom. We have to be understanding of other people and their beliefs to allow them to be free. We have to find the boundary between doing things because it is safer or easier and doing things because it preserves freedom.
We have to give up our own need to change everything and everyone around us to make sure that everyone is free, not just some. This seems dangerous, especially now, with all of the talk about terrorism and extremists, but we have to choose as a people whether it is better to die free because of some person that cracked (and would have probably been just as violent and crazy anyway) or to live constricted by rules and laws meant to "protect."