Aaron was also involved in some groundbreaking software development for political activism [1] [2]. I find it extremely easy to believe that someone in the DoJ saw that and decided to make an example out of him to dissuade other "hacktivists." [1] http://www.newyorker.com/online/blogs/newsdesk/2013/05/stron... [2] https://github.com/naomifox/mass-email-delivery-code
The smart people in law enforcement are scared sh*tless of hacktivists, so it's totally possible they lumped him in with the Sabu/Hammond/Lulzsec crowd.