This is a great overview of PIPA/SOPA:

Our #1 reason for fighting PIPA/SOPA is its impact on start up businesses. Protecting incumbent businesses (mostly Hollywood, network TV and 6 music companies) at the expense of innovation has never helped our economy. Please take action by contacting your senator or representative and encouraging them to vote against this bill.

Our sites will go dark on Wednesday, January 18th to protest this ill-conceived legislation. For further information, visit Stop American Censorship.