Those conspiracy theory actually provides good reading and keep people content rather than paying attention to most recent events.
I'm not sure how anyone can still hold this attitude.
Long before the snowden revelations, people who said that US agencies spy on everyone and collect data ignoring all laws have been ridiculed and called conspiracy freaks.
I do believe that the US government is behind ISIS, al qaeda, and other groups which they use for false flag operations and to justify tyrannical laws and military actions.
Using fear to manipulate the population is nothing new and have been used many times during our history.
Doesn't matter if all the allegation is true or not, it is pointless to go against the tide and not played by the rules.
Beside, Snowden might be getting false information on the level of competency of the intelligence community. If the intelligence is that good, we wouldn't have this much problem in the world now.