Actually this^ I'm not certain why it was downvoted but I had forgotten to take the Arab Spring into account and Egyptians organizing on twitter around the internet ban. Both have had... outcomes. But they were clearly necessary actions and twitter did help fuel that occurrence.

To contrast though, if a service being a premier source of propaganda (avoiding the question of this specific case since... politics) and offers no other value, then it's actually worse than trivial it's harmful.

So, it's a mixed bag. I still wish there was a better engineered platform than twitter out there though.