Moscow (CNN Business) On Friday, a controversial new law took effect in Russia: The so-called "sovereign internet" law, which mandates the creation of an independent internet for Russia.

In effect, Moscow has given itself the power to erect a sort of digital Iron Curtain around its networks. But will it force the change from a freewheeling internet to a purely Russian one?

That's what tech companies and Russian internet users alike will be watching as the law takes effect.

Here's what the measure entails: Earlier this year, Russian President Vladimir Putin signed into law new rules that would enable the creation of a national network that can operate independently from the rest of the world. Among other things, the law allows Roskomnadzor, Russia's telecoms agency, to shut the country off from external traffic exchange, creating a purely Russian web.

The government has said the regulations are part of an effort to protect Russia by creating the ability to sustain a fenced-off national network, in the event that a foreign power interferes with Russian cyberspace. The official newspaper Rossiiskaya Gazeta said the law coming into force should not affect internet users, but it "will ensure the availability of communication services in Russia in case of threats."

Now the government can directly censor content or even turn Russia's internet into a closed system." Rachel Denber, Human Rights Watch

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