General Motors insists that its do-it-yourself viral ad campaign for a Chevy SUV is a success, although some GM critics have hijacked the campaign, flooding the web with negative ads about the company, writes CNET. In a partnership with the "The Apprentice" TV show, GM launched a contest last month to promote the Chevy Tahoe SUV, calling on consumers to create a digital commercial about the SUV at Chevyapprentice.com.

Over the weekend, hundreds of people apparently began to circulate thousands of videos that charged GM with contributing to global warming, protested the war in Iraq or criticized the Tahoe's quality. Some contained profanity or sexually explicit messages. Late Monday GM announced that it would screen the ads for "offensive and inflammatory" content but said it would not remove material just because of a "negative tone" toward the company.

GM spokesperson Melisa Tezanos called the contest a success as a marketing campaign. "There are many different opinions and many different people, and we recognize that," Tezanos said, and noted that more than 80 percent of the commercials are favorable.

Users have submitted more than 21,000 ads and have emailed ads over 40,000 times; the site has generated 2.4 million pageviews; and the average visit to the site lasts more than 9 minutes, she said.