I'm not making any huge sacrifices, or changing my life for it, but, here's an example. If I happen across a one-sided argument, on Physics-Forums, I can jump in and put in my two cents. True, it's not going to change the world by itself, but I can lead by example. If two people see me doing it, maybe they'll jump in as well.
There are a lot of people that are doing a lot more than I am, of course. Look at the Occupy Wall Street movement. There are more and more people taking that chance of being ostracized, imprisoned; maybe they're not getting killed, but they're getting pepper-sprayed, and arrested.
They may not know exactly what needs to be changed, but they are willing to take the hard option and short-term pain. But I think that there's another point to be made here. The people in the Occupy Wall Street movement want to be a part of their government. They want to be part of the decision-making process.
But most of the people I talk to aren't in the Occupy Wall Street movement. They are people who listen to Christian radio stations, and try not to watch the news, because "it's usually bad news anyway," or "it's so boring" and they "don't know which side to believe." That's the scariest thing... We really don't know what to believe. It's this sense that "If I were compelled to act... what if I were on the wrong side?"
No, I think if people knew what to do, they would stand up and do it. The problem is that without transparency and accountability, nobody has any idea what to do. We know we're being lied to, but we don't know who is lying.