The PROTECT IP act is controversial because it gives the government broad powers to seize, block and filter websites, and even search engine results, for any website the government determines to be "endangering the public health". The MPAA/RIAA are the ones behind the scenes pushing for the act to be made into law, as it will shift the responsibility of fighting copyright infringement from a civil matter into the criminal world, and force the government to allocate tax payer resources to help the MPAA/RIAA fight net piracy and retain their existing business model.
With 100+ law professors already signing an open letter denouncing PROTECT IP as possibly "unconstitutional" and that it will "undermine United States foreign policy" if the US is to have its own web censorship filter, this week, prominent figures from the Internet industry have spoken out too against the controversial bill.
The founders of Twitter, Zynga, FourSquare, and top professionals from the likes of StackExchange, LinkedIn, and even Tim O'Reilly, of O'Reilly's series of tech books - a total of 193 entrepreneurs so far - have signed an open letter asking Congress to reconsider PROTECT IP. They've noted similar issues as has been noted before, including the irreparable harm the act could do to the DNS Internet naming system, as well as the broad nature of the act. They've also come out attacking PROTECT IP for putting unfair pressure on small start-ups and businesses, by shifting responsibility back to website operators, and watering down the DMCA's 'safe harbor' provision that currently protects them.
It is now up to the members of congress to heed these warnings, or to ignore them and ally themselves with the powerful copyright lobby.