While it looks like congress is back peddeling pretty quickly, they are still going forward with SOPA/PIPA which could fundamentally break the internet. Messing with the distributed nature of the internet will but the United States on par with some of the most aggressive censorship countries. In an open letter signed by the 83 high profile internet engineers including Vint Cerf a co-designer of TCP/IP explained their concerns that such legislation would damage the internet.
Below is a while a little outdated a very good explination of what SOPA/PIPA is:
PROTECT IP / SOPA Breaks The Internet from Fight for the Future on Vimeo.