Mr. Elturk said, “His father and family are really scared that he might do something.”

Attempts to Shut Down Blog

From time to time, Mr. Khan said, his father also cut off his Internet access and, to placate him, Mr. Khan recently added a disclaimer to his blog disavowing responsibility for the views expressed on the site.

He has also been fending off citizen watchdogs who are working to knock sites likes his off the Internet. Twice in September his blog went dark when his service provider shut him down, citing complaints about the nature of his postings.

Mr. Khan has now moved his blog to a site called Muslimpad, whose American operators recently moved from Texas to Amman, Jordan. Their larger forum, Islamic Network, is the host of discussions among English-speaking Muslims. One of their former employees, Daniel Maldonado, was convicted this year in federal court of associating with terrorists at their training camps in Somalia.

Mr. Khan said that he had dreams about meeting Mr. bin Laden and that he would not rule out picking up a weapon himself one day. In a recent essay, he argued that jihad was mandatory for all Muslims, and he cited three ways to fulfill this obligation: join fighters in Iraq, Afghanistan or Algeria; send them money; or promote militant videos as part of the jihad media.

For now, he said, he is fulfilling his obligations by helping other Muslims understand their religion. Recently he posted a video of a news report from Somalia showing a grenade-wielding American who had joined the Islamists.

“He is an example of a Muslim who follows the Religion of Islaam,” Mr. Khan wrote.