This short sentence has a powerful message, with a straight reasoning. I do not know, since when parts of our movement started to use it, but it is commonly used right now. The last time I read it was by Joshua Blakeny here http://www.rabble.ca/blogs/bloggers/campus-quotes/2011/02/has-national-post-declared-fatwa-911-studies (sorry "student" ;-), no offense)
Other researchers did use it as well.

But: Did Einstein said this? In wanted to know when and where he made it. I searched Wikiqoutes for it, but found nothing.
Only a similar statement, under missattributed:

I find it very inspiring and comforting to read quotes from those who have gone through great periods of struggle, so I put together some quotes in hopes that they will inspire and/or comfort others.

Enlighten the people, generally, and tyranny and oppressions of body and mind will vanish like spirits at the dawn of day. - Thomas Jefferson

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. - Galileo Galilei

A loud voice cannot compete with a clear voice, even if it's a whisper. - Barry Neil Kaufman

If you are out to describe the truth, leave elegance to the tailor. - Albert Einstein

The human race has one really effective weapon, and that is laughter. - Mark Twain

The high-minded man must care more for the truth than for what people think. - Aristotle

Sit down before facts like a child, and be prepared to give up every preconceived notion, follow humbly wherever and to whatever abysses Nature leads, or you shall learn nothing. - T.H. Huxley

Obstacles cannot crush me. Every obstacle yields to stern resolve. He who is fixed to a star does not change his mind. - Da Vinci

The most perfidious way of harming a cause consists of defending it deliberately with faulty arguments. - Friedrich Nietzsche