"Rights are like muscles, they disappear if you don't use them." --
Please read the whole thing. Here's an important excerpt:

We should always, especially when it is difficult, exercise our freedoms of speech and assembly, and I mean the word exercise. Rights are like muscles, they atrophy and aren't there when you need them if you don't use them. The first amendment is in trouble not just because of John Ashcroft and the USA Patriot Act, but because of a pall of self-censorship – some have spoken up with great courage, but many have been silenced not simply by the acts of the authorities but by the prison of their own fear. Still, if people could stand up to Pinochet, if the Mothers of the Plaza de Mayo could march in Buenos Aires during the time of the generals, if people spoke up in Prague in the 1980s, we can take a stand here, far more than we do. An atmosphere of repression exists specifically because people don't speak up against it. When you speak up, you are not repressed – you might be suppressed or punished, but you have freed yourself. Too, a tyranny can rise more easily by shutting up a thousand people than a million, and that's a reason to stand up and speak out.

(And here's the very important report she cites.)