An IEEE Spectrum podcast asks the question, Why Are Terrorists Often Engineers? The blurb:

With terrorism back in the news, so, too, is a curious footnote: Of the hundreds of individuals involved in political violence, nearly half of those with degrees have been engineers. This finding, first published in 2008, has been substantiated by two years of additional research by Oxford sociologist Diego Gambetta and political scientist Steffen Hertog, of the London School of Economics. Host Steven Cherry talks with Hertog about why terrorists seem to have a knack for engineering.

I have not listened to this, but the obvious answer would seem to be that many people might wish to be effective terrorists, but only the more technical ones have the needed skills to carry out an action that causes significant harm.  (I have often been thankful that the superb technical people I know appear to have no leanings in that direction.)

See also Open-Source Warfare and Extremist Engineers.

For now, nanotechnologies are primarily being developed by people who are not likely to deploy them for terrorist purposes, but as time passes this will change.  It took about a century for airplanes to be used outside traditional warfare to do major harm; probably that sequence will be faster for nanotechnologies.  We will need to model both offenses and defenses so that “white hat” nanotechnologists stay ahead; this proposal came from Mark S. Miller.  See the Foresight Guidelines and Open Source Sensing for further thoughts.  —Chris Peterson