Judy Shapiro, vice president of marketing for New York-based PalTalk, said the company is aware that there are Al Qaeda-focused rooms on its site, but if the chat occurring within those rooms does not violate the company's terms of service for troublesome language, freedom of speech applies.

"We absolutely shouldn't discriminate," she said. "We can't constrain people's ability to say what they want. If someone says, I am the head of Al Qaeda, come talk to me, that's perfectly legal."

In its terms of service, PalTalk lists "unacceptable conduct" that would violate those terms as "threatening, harassing, or intimidating another user" or "transmitting any unlawful, threatening, abusive, profane, offensive, defamatory, or hateful text or voice communication or images or other material, or any racially, ethnically or otherwise objectionable material, or any material that violates or infringes the intellectual property or privacy or publicity or other rights of any other party," among other kinds of behavior.

PalTalk will take down a chat room with no warning if users report trouble to its moderators. "If someone said, how do I create a bomb I can [detonate] in Times Square," that would obviously raise a red flag, Shapiro said.

In cases where "the level of language" would warrant an investigation, PalTalk would take whatever steps necessary to cooperate with law-enforcement officials or take down the site or both if there is good reason, she said.

In the meantime, others are doing their own part to take down jihadi Web forums, Kohlmann said. More than five of the top jihadi Web forums -- including ones called Al-Ekhlaas, Al-Hesbah, Al-Firdaws and Al-Boraq -- have been knocked offline since September, and several others that are still live such as Al-Shamikh, Majahden, and Al-Faloja "are suffering periodic blackouts which can last anywhere from several hours to a week in length," he said in the e-mail.

However, "you knock one out, another one pops up the next day," Kohlmann said at the conference, so just taking down the sites is not an effective way to stop cyberterrorists and would-be accomplices from meeting via online forums.

He thinks the real way for law-enforcement officials to hamper cyberterrorists and would-be accomplices using these sites is to join them and cause confusion and mistrust among their ranks.

"Infiltrating the system is most effective," he said. "People don't know if you're a real jihadi or an agent. These people have never met each other and if you give them a reason not to trust each other, that's all it takes" to disrupt their activities.