Perhaps for the same reason we normally don't like to have names of street gangs published or too much publicity around gang crime. It emboldens the criminals, who desire the acclaim and notoriety, why help them be famous? Maybe they think it will increase their virgin allotment if they get their mugs on the news.
The Imam lied about the 72 virgins thing -- it's really a 72-year-old virgin whose idea of paradise is to just keep kicking Mohammad in the groin.