Does YouTube have a control problem?

"This is to notify you that we have removed or disabled access to the following material," YouTube wrote to Rook in an e-mail, which was obtained by CNET News.com. The trailer for his documentary was removed because Viacom had claimed that his documentary had infringed on the company's copyright. Rook said not one frame or one piece of music from his film about a gay professional wrestler belonged to Viacom.

Rook's film clip was mistakenly pulled as part of YouTube's effort to sweep the site of content owned by Viacom, he said. (YouTube did not return an e-mail requesting more information about about why Rook's clip was taken down.)

ZDNet reported that another YouTube user was accused of violating Viacom's copyright when he posted a video of a "Sunday night dinner at Redbones in Somerville, Mass." The man denied that there is anything of Viacom's in his "friends and family" video.

The parent company of Comedy Central and Nickelodeon demanded Friday that YouTube remove 100,000 clips from the site that feature Viacom shows. The number of videos is three times more than the 30,000 videos that the Japanese entertainment industry demanded YouTube pull last October.

"I know it was probably an accident that mine got taken down," said Rook, 43, adding that he's nonetheless disappointed. He added that he wonders whether the video-sharing company has enough control over the site.

Control has been a central issue during YouTube's rapid evolution as the Internet's first real entertainment network. For instance, big entertainment companies have always wanted YouTube to exercise more control over users who post pirated clips from some of the entertainment industry's hottest shows. The break with Viacom has some analysts wondering whether the lack of authority over what happens on the site may hurt the year-old YouTube as it negotiates licensing agreements with major film studios and TV networks.

"The paradox for YouTube is that they need to figure out how to play well with the big boys," said Todd Chanko, an analyst with Jupiter Research. "These legal cases and public relation troubles will continue to hurt their image with the large media companies."

Executives at YouTube, acquired by Google for $1.65 billion last October, have steadfastly argued that it's not their job to police their site. As an Internet service provider, YouTube says the law doesn't hold the company responsible for the actions of its users, but will quickly respond to complaints by copyright holders.

"We take copyright issues very seriously," a YouTube spokesman said in a statement on Thursday. "We prohibit users from uploading infringing material, and we cooperate with copyright holders to identify and promptly remove infringing content."

But as YouTube's leaders seek partnerships that would give the video-sharing site access to professionally crafted content, they may find that adhering to the strict letter of the law won't make them many friends in Hollywood, where they want tough protections for their materials.

YouTube doesn't prescreen any of the more than 60,000 videos posted to the site each day. The company relies on content holders and users to report any violations of the company's terms of use. This, say YouTube critics, does not adequately safeguard copyright. An example of how long unauthorized video can stay on the site without being flagged came Thursday.

For the past three months, an employee at Gawker Media has posted video clips onto YouTube from TV shows produced by such companies as NBC, CBS, CNN and ABC, CNET News.com reported Thursday. Two copyright holders, including a Fox affiliate in New York, said that Gawker, which operates 14 blogs, including Valleywag and Fleshbot, was unauthorized to use their material.

Gawker Media owner Nick Denton has acknowledged that an employee posted the videos. He has declined to comment on why the employee posted the clips.

The poster added a new twist to uploading unauthorized copyright material by inserting into the clips advertisements for Gawker-owned blogs. Two videos about comedienne Rosie O'Donnell were each viewed more than 400,000 times.

Executives at two companies said they wanted to know how the videos could go unnoticed for three months and how can copyright owners prevent others from repeating the tactic.

"We showed (the videos posted to YouTube by the Gawker employee) to some of our legal and tech people," said one executive at a major media conglomerate. "They couldn't believe it. They also couldn't believe it hasn't happened before. They hated that someone was doing it, but one guy admitted he thought it was brilliant."

Unclear is whether some of the bigger media companies plan to respond to the postings.

Chanko said the case is an example of just how difficult it can be to protect copyright in environments like YouTube's.

"There's just no bonafide system available that would enable YouTube to monitor all the video on its site," Chanko said. "There are attempts to create intelligent video sensing...who knows? Maybe in five years we'll see it."