He argues that more such "celebrity terrorists", who have the power to inspire their followers while intimidating their enemies, are bound to emerge.
Terrorism is a form of political theatre, and there are two audiences that contemporary terrorists seek to influence: the intimidated and the inspired. The intimidated are those whom the terrorists attack, and those who identify with the terrorists' victims. Terrorists also use their violence to communicate with each other and their sympathizers – the inspired.
The increasingly dominant culture of celebrity, which produces a profound discomfort with anonymity, evokes among the alienated an urge to rage against obscurity. But it’s not just about ego, it's also crucial to the viability of a terrorist campaign. Without the ability to attract attention, peddle inspiration, and impress fellow travelers with one's commitment and ingenuity, a terrorist campaign will not be able to generate the footsoldiers, finances, and facilitators it needs.
Which, I think, explains why Al Qaeda followers are so obsessed with blowing up planes and other grandiose plots such as the Mumbai attacks. As Wesley notes, such plans are much harder to pull off without detection than simply sending anthrax in the post or stabbing random people in the street.
But sweeping, theatrical acts of terror are more inspirational to other potential terrorists and create more concentrated fear among everyone else. I also suspect that the obsession with grand plots has something to do with the narcissism of those who become entangled in terrorist cells.
I would add, though, that the "urge to rage against obscurity" is nothing new. Just read Crime and Punishment (first published 1866).