Iraq’s sectarian war is spreading onto the Web. Some Iraqis, like Kika, have been forced into hiding or exile after being targeted on the Internet. Others may have run too slowly. Sunni and Shiite Web sites offer warnings to Iraqis about neighborhoods and ministries that may have been infiltrated by militias, but the sites are also increasingly used as tools by those seeking names, addresses and occupations of citizens to kill. (NEWSWEEK has found at least eight of these sites, but we have decided not to publish their Web addresses.) The outings are openly endorsed by some Iraqi leaders. Jalal al-Din Saghir, an influential Shiite cleric and parliamentary deputy, sponsors several sites. “Some of the Web sites can be used to catch spies by tracking their movements,” he told NEWSWEEK.

Rising sectarian violence has become the No. 1 threat to Iraq’s stability, with more than 2,500 Iraqis killed violently in September. Much of the killing is linked to death squads in Iraq’s heavily Shiite police force, an agency that would scarcely exist without U.S. training and funding. Last week the U.S. military removed an entire Iraqi national police brigade from duty after American soldiers received reports that the unit was involved in death-squad activities. Military investigators are tracing possible links to the notorious Mahdi Army militia, which is believed to be running Shiite death squads in Baghdad. Efforts to build a reliable Iraqi police force seem nearly hopeless anyway: this summer alone the Interior Ministry reportedly fired at least 1,700 bad cops.

And the violence in the streets keeps getting nastier. Until recently, death threats in Iraq arrived the old-fashioned way–a flier found on a family’s doorstep, warning them to leave the neighborhood or suffer the consequences. Now Iraq’s sectarian killers have discovered the anonymity and long reach of the Internet.

Sunni sites provide Arabic-speaking users with a place to swap information–true or not–about alleged collaborators with Shiite death squads in Baghdad. One site’s Iraqi correspondents write in with news and views–as well as exposés of corrupt officials or snitches alleged to be aiding the death squads. One of the site’s organizers, Ali Ahmad, denies that he promotes violence with his site, and says he just “publishes information to fill a vacuum that the authorities can’t. People can’t go to the police,” says the 48-year-old, an Iraqi exile and British citizen. Last week the site published a warning “not to go to the Ministry of Higher Education to accept fellowships, because it is a trap by a death squad.” Another site lists more than 300 names, birthdays and locations of suspected Shiite militia members. Shiites have sites of their own, where believers are urged to avenge suicide car-bomb attacks by slaughtering Sunnis. “Let’s torture them and don’t be silent,” wrote one recent poster.

The U.S. military tries to monitor the e-traffic, hoping to head off the killers. But the stepped-up drive against the death squads is tough on both sides: last week at least 13 U.S. troops were killed in Baghdad, one of the city’s worst weeks for Americans since the war began. More bad weeks may be ahead as the fight continues. One post last week offered advice to members of the Mahdi Army on how to avoid capture by U.S. forces. “Don’t wear black,” the writer advised, referring to the standard Mahdi Army uniform. Other tips: “Hide your weapons,” don’t stand in groups, and “never admit you’re a member of the militia.” Just what Iraq needs: online hints for sectarian butchers.