I’ve seen various references to how this latest plot provides evidence that the composition of would-be bombers has expanded into the middle class. For example, according to the Wall Street Journal, the profile of potential terrorists has widened significantly thanks to the Liqui-bombers:

As British police piece together the alleged plot to down airlines over the Atlantic, emerging details point to a troubling — and growing — strain in Islamic terrorism in Europe: the involvement of women and middle-class, university-educated young men.

The origins of the plot date back to before the July 2005 London bombings, according to a person familiar with the matter, and involved a wide group of alleged plotters. At least three of the detainees rounded up last week are women, according to Hanif Qadir, who runs a youth group in east London, where many of the suspects lived. Most of the men were middle-class, many with jobs. One was a student and head of an Islamic society at a large London university.

They are a marked contrast to the stereotype of a homegrown Islamic terrorist as a disaffected young man on society’s fringes, such as Richard Reid, the British citizen who unsuccessfully tried to ignite a shoe bomb on a Miami-bound flight in December 2001.

(emphasis mine)

Given that we will never know if they were for real or not and that even in the UK, the odds of someone who is arrested being convicted of anything, much less terrorism, is only 2%, we don’t actually know if the profile of terrorists has changed or not.

What has really changed in our knowledge about the composition of the would-be-terrorist community? At this time, nothing.

Empirically, the population of proven terrorists seems to be composed primarily of disaffected, slightly unstable young men and men who come from old money.

A nice bit of research can be found in Marc Sageman’s book “Understanding Terror Networks” - you can also order a C-SPAN discussion of this at http://www.c-spanstore.org/shop/index.php?main_page=product_video_info&products_id=190022-1

He gives a much better profile of active terrorists that attack the West - think 2nd or 3rd generation immigrants in Europe from Islamic cultures (with a decent education, family and income).