The Tunisian government was able to block YouTube and Dailymotion
YouTube had a much better coverage of the events than traditional media. And the government's censure was to some extent effective in blocking access to it (as to other video sites such as Dailymotion, the French equivalent of YouTube). YouTube and Dailymotion are just inappropriate to the task.
For instance, a good collection of 134 YouTube videos was assembled in the "
Freedom for Tunisia" website. This amounts to 1 or 2 GB of data and can easily be mirrored in such a way that no government will be able to block access to it without blocking all access to Internet.