I think we might see a lot of incidents like this in the years to come - embittered people who have seen their lives fall apart in the credit crunch, lost their homes, farms, whatever, lash out at the government, the banks, big cities, whatever is convenient and sufficiently 'other' to project their self loathing and sense of failure on to.
1 - "Times Square Bomb Scare: Foreign Militants, or Homegrown Terror?" by Howard Chua-Eoan. Published by time, 2nd of May, 2010. (http://www.time.com/time/nation/article/0,8599,1986469,00.html)