Search for the Muslim Brotherhood on Facebook, and you'll probably find little more than an unofficial community page whose members barely exceed 120  -- although, amusingly, one of them happens to be somebody posing as Tariq Aziz, Saddam Hussein's former deputy. (For the record, "Aziz" likes to read the Quran and his favorite film is a 1991 Indian romantic drama called "Godfather.") From its absence on Facebook -- one of the largest social networks on the planet with over 400 million users -- the Muslim Brotherhood would seem to have a pretty feeble Web strategy.

But appearances can be deceptive. In fact, the powerful Egyptian opposition group has an entire collection of Web apps devoted to advancing its message. Now, soon to be joining IkhwanWiki, IkhwanGoogle, and IkhwanTube -- "Ikhwan" means "brotherhood" in Arabic -- will be IkhwanBook, the Muslim Brotherhood's own rendition of Mark Zuckerberg's Internet cash cow. The site is already live and runs on open-source code that seeks to clone the real Facebook. A Facebook Connect button is displayed prominently on the homepage, hinting that new users will be able to log in with their existing Facebook credentials, but unfortunately, the button isn't functional -- and it's unlikely that it will ever be.

Since Facebook can delete accounts that are the target of complaints, engineers for the Muslim Brotherhood say it's only natural to develop alternatives like IkhwanBook. It's a space that isn't in danger from the government in Cairo, which could bring down a Brotherhood Facebook page with enough pressure on the California company.

Can IkhwanBook succeed? At a time when walled gardens are going out of style -- except perhaps in the news industry, but that's for another day -- a walled garden like IkhwanBook gives members a relatively private place to chat and organize. Reaching out to new networks and audiences, though, will probably be more difficult. Successful social networks expand by creating new bridges among lots of different interests rather than reinforcing interest in a single subject.