The Congressional International Anti-Piracy Caucus has called Pirate Bay one of the six worst pirate organisations in the world.
Its report, the 2010 International Piracy Watch List, compares copyright violators to drugs traffickers and arms smugglers, claiming they use the same distribution networks.
Other highlighted sites are China’s Baidu - the country's biggest search engine - Canada’s IsoHunt, Ukraine’s mp3fiesta, Germany’s RapidShare, Luxembourg’s RMX4U.com - some of the most popular websites in the world, says the caucus.
This is despite a German court ruling earlier this month that RapidShare wasn't responsible for the content hosted on its site.
"International piracy of American intellectual property weakens a segment of our economy that long has supported innovation and great American jobs," said Senator Sheldon Whitehouse.
"Congress must work on a bipartisan basis to protect the creative industries and the jobs they support. The United States has been on the losing end of the largest theft of intellectual property in history. This must be stopped, and soon."
The worst piracy is to be found in China, Russia, Canada, Spain, and Mexico, says the report. It singles these countries out not just for the scale of piracy but for the 'lack of political will to confront the problem', and says little progress has been made in the last year.
"What is stunning is that piracy isn’t just emanating from countries like Russia and China, but also from Canada and Mexico, our largest trading partners," said senator Orrin Hatch.
"Now is the time for policymakers to come together to tackle this global threat that cripples economic growth and stifles the innovation that has made our nation great."