In a letter dated Oct. 14, YouTube Chief Counsel Zahavah Levine said the site removes clips once it receives takedown notices because the Digital Millennium Copyright Act requires it to do so to avoid liability for infringement.

Levine also specifically rejected the McCain's campaign request that YouTube give preferential treatment to clips uploaded by candidates. "While we agree with you that the U.S. presidential election-related content is invaluable and worthy of the highest level of protection, there is a lot of other content on our global site that our users around the world find to be equally important--including, by way of example only, political campaigns from around the globe at all levels of government, human rights movements, and other important voices," Levine wrote.

In recent months, both the McCain and Obama camps have uploaded clips to YouTube only to see them taken down for alleged copyright violations. Among other clips, the video-sharing site recently removed a McCain campaign video that made use of footage showing CBS anchor Katie Couric and one that showed Fox correspondent Major Garrett. While the Digital Millennium Copyright Act allows uploaders to challenge takedown requests, restoring a video can take up to two weeks.

Even when YouTube deletes clips, candidates can still post them elsewhere, including the campaigns' sites. But Michael Bassik, vice president of interactive marketing at political marketing firm MSHC Partners, said that's no substitute for using YouTube.

"As the largest site on the Internet for video streaming and distribution, YouTube is hands down a critical component to any modern campaign's ability to distribute videos to voters and the media," Bassik said.

The McCain campaign's general counsel, Trevor Potter, complained on Monday to Google that the clips complained about were "clearly privileged under the fair use doctrine" and asked that YouTube review clips posted by presidential candidates before removing them.

But Levine countered that figuring out whether a clip made fair use of material was rarely easy. "Lawyers and judges constantly disagree about what does and does not constitute fair use," Levine wrote. "YouTube does not possess the requisite information about the content in user-uploaded videos to make a determination as to whether a particular takedown notice includes a valid claim of infringement. The claimant and the uploader hold all the information in this regard, including the actual source of any content used."

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