If The Empire passes SOPA or PIPA it will ruin the internet and create one of the greatest infringements of freedom in history.
The Khan Academy does a great job of simply explaining how disgusting these proposed bills in the U.S.A are and why they will literally impact on the rest of the world.
Notice that Salman Khan point out that this is a Shoot first, ask questions later approach with no legal ramifications for the accuser.
Clay Shirky gives a talk for Ted that shows just how insidious these potential laws can be.
Notice where Clay points out that it is a copyright violation for a cake shop to print a child's drawing of Mickey Mouse on that child's own birthday cake.
Information on protests against SOPA (including the Internet Blackout of Jan 18 2012) can be found in this Wikipedia article.