Google, Facebook and Twitter may be fierce competitors, but they stand united this morning in opposition to a pair of bills before Congress that are designed to deter online piracy but would also shackle website operators and service providers with policing burdens so onerous as to endanger innovation.

The Senate Judiciary Committee tomorrow is scheduled to hold a hearing on the Stop Online Piracy Act, which proponents say would provide new legal tools to target "rogue websites" that traffic in pirated goods, both physical and digital. In a letter of opposition to the committee dated today, the three Internet giants are joined by AOL, eBay, LinkedIn, Mozilla, Yahoo, and Zynga under the umbrella of an advocacy organization called Protect Innovation.

The letter reads in part:

We support the bills' stated goals - providing additional enforcement tools to combat foreign "rogue" websites that are dedicated to copyright infringement or counterfeiting. Unfortunately, the bills as drafted would expose law-abiding U.S. Internet and technology companies to new uncertain liabilities, private rights of action, and technology mandates that would require monitoring of web sites. ...

The companies are most concerned about the legislation's potential to damage "safe harbor provisions" in existing law that limit the responsibilities and liabilities of content hosts:

One issue merits special attention. We are very concerned that the bills as written would seriously undermine the effective mechanism Congress enacted in the Digital Millenium Copyright Act (DMCA) to provide a safe harbor for Internet companies that act in good faith to remove infringing content from their sites. Since their enactment in 1998, the DMCA's safe harbor provisions for online service providers have been a cornerstone of the U.S. Internet and technology industry's growth and success. While we work together to find additional ways to target foreign "rogue" sites, we should not jeopardize a foundational structure that has worked for content owners and Internet companies alike and provides certainty to innovators with new ideas for how people create, find, discuss and share information lawfully online.

As for tomorrow's judiciary committee hearing, it would appear to be shaping up as more of a pep rally for the legislation than any honest airing of the merits, according to this report on Techdirt, which notes a speaker lineup that can only be described as a stacked deck. Five supporters of the legislation are scheduled to speak, while only one opponent - Google - is on the agenda.

Welcome regulars and passersby. Here are a few more recent buzzblog items. And, if you’d like to receive Buzzblog via e-mail newsletter, here’s where to sign up. Follow me on Twitter here and on Google+ here.