If hijacked sites and hosting companies that fail to police malware distribution sources represent two of the most serious threats to Internet security, there may be hope for improvement, according to researchers working with Harvard Law School's StopBadware.org. After publishing a list of rogue Web site hosting companies and launching a campaign to label every malicious site they can find on the Internet, an effort that has filtered out over 600,000 nefarious applications thus far, the StopBadware team says that people are responding.