State Department specialists have replaced anti-American ads put on Yemeni websites by al-Qaida with postings that detail the "deadly impact of al-Qaida tactics on Yemenis themselves," Associated Press correspondent Kimberly Dozier reports.

Secretary of State Hillary Rodham Clinton talked about the successful hacking of the terrorist network's online efforts during a conference Wednesday in Tampa that was attended by "hundreds of U.S. and international special operations commanders," Dozier adds.

Clinton told the group that because of the State Department's effort, "extremists are publicly venting their frustration and asking supporters not to believe everything they read on the Internet."

Evan Kohlmann, a consultant on terrorism issues who tracks such websites, tells The Washington Post that highlighting the deadly effects of al-Qaida's actions does do "a tremendous amount of damage" to the network's image, "recruitment campaigns and its effort to launch renewed attacks." But he has doubts about whether the websites that State has hacked reach a very wide audience.