Online movie and TV pirates are becoming craftier — necessitating a “focused, strategic U.S. policy” — the Motion Picture Association of America says in a filing to the Office of the U.S. Trade Representative (USTR) released today. The trade group is helping the USTR to determine its fourth Notorious Markets List, which the government uses to shape its enforcement plans. MPAA identified at least 21 websites as well as dozens of locations that tolerate sales of pirated DVDs. As you might expect, many are based in China, Russia, and Eastern European countries including the Ukraine, Romania, Estonia, and Latvia. But the Netherlands, Germany, Canada, Switzerland and Brazil also harbor some of the worst offenders in the trade group’s eyes.

Content thieves “are taking advantage of a wide constellation of easy-to-use, consumer-friendly online technologies such as direct download and streaming cyberlockers, which, in turn, have given rise to a lucrative form of secondary infringement on the part of ‘linking sites’ that index stolen movie and television content hosted on other sites,” the MPAA says. They’re difficult to nail because “some of the operators of the linking sites and hosting platforms (cyberlockers) operate anonymously and outside the boundaries of the law.” Leading offenders, it says, include Russia’s well-known VK.com and Rapidgator.net.

It’s a lucrative business. A recent study of 30 direct download and streaming cyberlockers by NetNames and Digital Citizens Alliance found that they generated nearly $100 million in annual revenue from ads and subscriptions with profit margins as high as 88%.

“The film and television industry is a vibrant component of our nation’s economy, supporting close to 2 million jobs and generating a positive trade surplus in every country in the world in which it does business,” says MPAA chief Christopher Dodd. “Robust protection and enforcement of intellectual property rights both domestically and abroad are vital to ensuring the sustained growth of America’s creative industries.”

The trade group says the list it gave to the USTR isn’t comprehensive, but indicates “the scope and scale of global content theft and some of the ongoing challenges rights holders face in protecting their intellectual property.”