Internet operators

China is moving to rein in Web sites it deems inappropriate. The Communist nation has targeted Google and Baidu, the two dominant search engines there. The charge is spreading pornography and vulgarity.

China's Ministry of Public Security and six other government agencies launched the campaign on Monday.

The government "decided to launch a nationwide campaign to clean up a vulgar current on the Internet and named and exposed a large number of violating public morality and harming the physical and mental health of youth and young people," said a report on state television.

Attackers bent on shutting down large Web sites -- even the operators that run the backbone of the Internet -- are arming themselves with what are effectively vast digital fire hoses capable of overwhelming the world's largest networks, according to a new report on online security.

In these attacks, computer networks are hijacked to form so-called botnets that spray random packets of data in huge streams over the Internet. The deluge of data is meant to bring down Web sites and entire corporate networks.