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.

All of these censorship regimes exist with varying degrees of coerced self-censorship brought about by threats of punishment for posting content deemed immoral or harmful to the state. Users and companies are aware that their online activity may be monitored at any time and themselves become players in creating a censorship environment.

North Korea's 'Walled Garden'

Operating as a nationwide intranet, a truly sovereign system can only be accessed from within the state. The one standout "success" in this complete censorship regime is North Korea's Kwangmyong (Bright) network. There is little information about the network because few people outside the so-called "hermit kingdom" have been able to access it. But according to a report by the AP news agency, the system contains up to 5,500 websites that are mostly associated with universities and government-run entities.

This type of network is one that can really only work in places where there is a virtual blockade on information from the outside world, such as North Korea or Cuba, which has a similar system. This type of domestic intranet environment is also difficult to establish in all but the most oppressive societies because experience with the free-wheeling way the Internet works already exists.

China's Great Firewall

China's "Golden Shield" project, which blocks and filters content deemed harmful by the ruling Communist Party, has been largely successful because the government decided early on that the Internet was something that needed to be controlled. As Internet use grew rapidly in the first decade of the 21st century, homegrown sites that accepted the authorities' censorship rules—and assisted in blocking content—became the norm. While Western companies have struggled to or refused to adapt to the rules governing content-filtering, domestic companies like Baidu, the country's largest search engine, have thrived.

Chinese users wishing to access blocked sites can use proxies, which provide access to third-party servers to avoid censors, but because the web already caters to the domestic audiences, most users will not go through the effort of doing so.