Glenn Kates

In Russia, it is unclear how users will react to the new reality being created around an Internet that was once widely free.

In April, the State Duma passed legislation that would require non-Russian tech companies to store all domestic data within Russia for at least six months. And Kommersant, a well-regarded newspaper, reported that a commission set up by Russian President Vladimir Putin is recommending a system that would allow the government to filter and access all content passing through Russian servers.

It is still unclear whether major companies like Google and Facebook will agree to the expensive task of placing servers and data-storage centers inside Russia -- or if Moscow will follow through with blocking access to the sites if they do not.

Whatever he decides to do, Putin is representative of an accelerated push by autocratic leaders worldwide to reign in the unwieldy Internet space. But doing so once populations have already experienced the value and convenience of open access can be difficult.

Here's a look below at some case studies of web censorship -- ranging from the most extreme version of a truly "sovereign" web to one of evolving ad-hoc efforts to chip away at Internet freedom.