A radical Islamic Web site systematically tracks Christians on PalTalk.com, an Internet chat service on which a New Jersey man received a death threat two months before he and his family were murdered. The password protected Arabic Web site, at the address www.barsomyat.com, features pictures and information about Christians who have been particularly active in debating Muslims on PalTalk.

One page from barsomyat.com features a group of photographs of a Syrian Christian, “Joseph,” who now lives in Canada. Barsomyat.com’s users have posted personal information about Joseph, including his brother’s parole status, and make clear that they are actively trying to track down his current address.

Subscribers also post explicit warnings to Joseph. One comment states, “Know, oh Christian, that you are not far from us and you are under our watchful eyes!” Another user remarks, “Laugh, oh Christian, and soon you will see a big hit.”

Ahmed Paul, an Egyptian Christian and a theology student in America, said he believes Joseph was targeted because he frequently engaged in debates with Muslims on PalTalk. The Internet chat service attracts up to 3 million users a month, and subjects range from movies to music to religion to adult topics – and some Arabic-speaking users of PalTalk have reported that contentious debates between Christians and Muslims are common in certain chat rooms.

Hossam Armanious, a Coptic Christian from Jersey City, N.J., who was found murdered earlier this month, frequently debated with Muslims on PalTalk. Two months before Armanious’s murder, authorities said he received a death threat from a Muslim PalTalk user: “You’d better stop this bull … or we are going to track you down like a chicken and kill you.” On January 14, Armanious and his family – including two daughters, ages 15 and 8 – were found killed in their Jersey City home, bound and gagged with their throats slashed.

Authorities have not determined whether Islamic extremists are to blame for the Armanious family’s murder, nor is there any apparent link between the murder and barsomyat.com’s tracking of Christians on PalTalk. However, many barsomyat.com users expressed jubilation at the deaths.

One user posted a photograph of Hossam Armanious and wrote, “This is a picture of the filthy dog, curser of Muhammad, and a photo of his filthy wife, curser of Muhammad. They got what they deserved for their actions in America.”

In all, about 40 different discussion threads on barsomyat.com berate the Christians of PalTalk, and there are at least seven collections of photographs of PalTalk Christians. The barsomyat.com discussion threads seem to focus on Arabic-speaking Christians rather than those who speak English.

Barsomyat.com features not only photographs of the targeted Christians, but also attempts to track down their addresses. A post about a Christian man whose computer was apparently hacked to obtain his photograph includes the man’s PalTalk name, his real name, and the city where he resides in Lebanon.

Another barsomyat.com entry outlines the relations (both blood and marital) between four Christians who are apparently PalTalk users, posts photographs of them, and then states, “We have postponed publishing this information because there is a lot more to be revealed when the time is right.”

Even barsomyat.com’s banner displays its hatred of Christians. The banner displays a crucifix crossed out by a violent red “X,” and the main heading reads in Arabic, “Christians: Revealing the Truth Behind Our Belief.”

Judging by the posts, almost all of barsomyat.com’s users are Middle Eastern, and they are predominantly Egyptian. Mr. Paul said that’s significant because the extremists on barsomyat.com live in societies where people simply do not challenge Islam and would never dream of insulting Prophet Muhammad.

Mr. Paul, who is an Islamic convert to Christianity, said when Islamic radicals from such societies participate in Internet debates with Christians who live in societies that promote free speech, they are often shocked by the Christians’ arguments and view their debating opponents as blasphemers. And in the eyes of Islamic extremists, blasphemers are worthy of death.

Author Robert Spencer, who has been following the Armanious case for his Web site Jihad Watch, described barsomyat.com as “extremely important” after it was shown to him.

“I have never seen anything like this before,” Mr. Spencer said. “It’s chilling to see photographs of people who probably have no idea that they’re on the Web site. Hamas’s Web site would post self-congratulatory accounts of their attacks on civilians, but barsomyat.com’s users are telegraphing their intended victims in advance.”

Mr. Spencer added that barsomyat.com is a “prime example” of how some Islamic extremists can utilize technology to attempt to bring Islamic religious law to the West.

“We saw in the Theo van Gogh murders that some Muslims will take these kinds of matters into their own hands,” Mr. Spencer said. “The Internet makes it easier for them to do so by disseminating this kind of information. You could imagine 15 years ago how hard it would be for people to get this much information on people who they believe should be killed.”

Barsomyat.com is registered to Viza-Web Inc., a Web hosting company based in Woodbury, Minn.