When regimes are shutting down the Internet it is usually far too late.

The Internet is a very powerful tool in the early stages of a protest movement. It allows people of like mind to connect and form a critical mass.

This is not a recent ‘discovered’ use of the Web, for some of us, it was the point of building the Web in the first place. The Web started in the early 90s in the wake of the year of miracles and the fall of the Berlin Wall. The Web provided a model for extending the reach of that movement - see http://www.youtube.com/user/hallambaker#p/u/0/PyD2rhI4ZGk

The Web is still a useful resource when a dispute has moved into the streets but it is no longer an indispensable one. By that time the protest movement has formed its own communication infrastructure independent of the Internet. Shutting down the Internet does not end the protests, it is more likely to convince passive supporters of the opposition to come out onto the streets to support them.

Repressive regimes survive by convincing people that they are going to persist forever. That is why there is a domino effect in the Arab Spring. Once people in Egypt realized that the corrupt regime of Ben Ali was falling they realized that their own government was vulnerable. Many of the people who hated the Mubarak regime but had been prepared to support it out of self-interest suddenly withdrew their support.

Shutting down the Internet demonstrates that the government is concerned about its survival. It is a demonstration of weakness, a panic move that demonstrates that the crisis is moving into a terminal phase.