Is there any evidence to support that these petitions have done anything that wouldn't have already been done? They seem like a red herring.
So the questions I'd ask about whether petitions work are: -will they work to get government to reconsider policies? -will they reveal government's unwillingness to act?
Either way, that's a victory in my books.
One major objective of activism is to inspire more activists.
At worst, it shows that a lot of people are listening and agreeing with Snowden regarding NSA's snooping