I have to disagree with Jnevis on some things.
By the theories set forth in the 60's the purpose of "terrorism" is to instill "terror" or extreme fear, into a particular group.
The purpose of even "peaceable assembly for redress of grievances", as acknowledged under the Constitution, is to cause extreme fear of unemployment among politicians. So by that definition ALL popular (grass roots ) political protest is "terrorism".
Jnevis is absolutely correct when he states that the Founding Fathers were "Terrorists", what else would you call an organized group that assaulted Govt. officials, (Ma. RI., NY, and SC ) destroyed property, (Ma, RI, NY, SC, ) and Raided government stores for arms (NH ), not to mention infiltrating military organizations with the intent of resisting legal authority (all 13 Colonies ).
Simply put, a disgruntled populace has little chance of standing against a trained military force in conventional battle due to disparities in training, experience, and supply. Therefore the only practical method left for resistance is the hit and run tactics of unconventional warfare using every subterfuge and diversion to allow the inferior force to achieve local superiority.