The battle lines over online copyright enforcement sharpened on Thursday when dozens of prominent high-tech entrepreneurs and investors signed a letter urging members of Congress to reject the PROTECT IP Act. The legislation, which has been making rapid progress through Congress in recent weeks, would establish a blacklist of "rogue sites" and compel a variety of intermediaries to block access to them. It is strongly supported by Hollywood and the recording industry.

"We think PIPA will ultimately put American innovators and investors at a clear disadvantage in the global economy," the letter states. It praises section 512 of the DMCA, which gives online service providers a "safe harbor" from copyright liability if they promptly remove infringing materials. They warn that the PROTECT IP Act will upset the "delicate balance" embodied in this provision.

The list of signers includes a who's who of the startup scene: Netscape founder Marc Andreessen, publisher Tim O'Reilly, and dozens of prominent angel investors and venture capitalists, both inside and outside of Silicon Valley. They write that the legislation "puts burdens on countless Internet services" that meet the legislation's broad definition of "information location tools." And they warn that forcing DNS providers to participate in the blacklist will undermine Internet security.

They also fault the legislation for creating a "private right of action" for copyright holders. Service providers would have to deal with demands not only from the government but also from private copyright holders. They note that copyright holders have expressed concern that the Department of Justice wouldn't have enough resources to initiate action against all the "rogue sites." But "why should costs be shifted to innocent Internet entrepreneurs," they ask, "most of whom have budgets smaller than the Department of Justice?"

The letter reflects the ongoing tension between California's two powerhouse industries, and it closes with an explicit swipe at Hollywood. "Pirate web sites will always exist," the tech luminaries write, "but if rights holders make it easy to get their works through innovative Internet models, they can and will have bright futures."

Silicon Valley isn't the only source of opposition to the PROTECT IP Act. The New York Times came out against the legislation earlier this month. And there are voices of opposition even in Hollywood's backyard, with the Los Angeles Times calling for the bill to be rejected in favor of a "a more measured approach" to the problem of rogue sites.

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