It seems as if the SOPA protests were quite effective. 162 million visitors of Wikipedia saw the message. Zuckerberg's Facebook post got half a million Likes. Thousands of bloggers downloaded protest plugins which blacked out their blog.
See also
- SOPA Opera: Where Do Your Members of Congress Stand on SOPA and PIPA?
- ArsTechnica: PIPA support collapses, with 13 new Senators opposed
- Wikipedia: Protests against SOPA and PIPA
- German News: heise, heise, Golem, Golem