A commentary by Raffaello Pantucci, now @ RUSI, whose has written on 'lone wolves' before and this point is well made:
The key conclusion for security agencies is that such terrorist cells are notoriously difficult to uncover prior to event. Some work can be done in targeted public information campaigns aimed at chemical companies, storage firms or other industries that might be conduits for individuals to obtain transformative material for homemade explosives. This will help give authorities leads like those that led to Khalid Aldawsari's detention.
The case referred to in Texas I'd forgotten:
...Aldawsari attempted to purchase chemicals from the Carolina Biological Supply company, using a commercial shipping company to have them delivered to his home in Lubbock, Texas. Both the chemical company and the shipping company flagged the purchase as one of concern to authorities, leading to an investigation by the FBI that uncovered Aldawsari as a loner terrorist cell building a bomb whose diary was full of menacing jihadist ideas. He was convicted in November last year and sentenced to life imprisonment.
Link:http://www.rusi.org/analysis/comment...ikPxU1.twitter