TO HEAR AN independent voice in Vladimir Putin’s Russia, you can’t turn on the television or read most newspapers. But you can — so far — log onto the Internet.

Anti-corruption blogger Alexei Navalny has become one of the most prominent anti-Kremlin figures in Russia. Opposition groups organized mass protests in major Russian cities last year on social networking Web sites. The Kremlin, therefore, has decided to tighten its grip on the Web.

The Russian government this month began implementing a new Internet filtering policy, including a blacklist of banned Web sites. The policy is supposedly about protecting Russian minors from material about suicide, drugs or child pornography. But human rights advocates warn that the policy is intended to silence legitimate, independent speech in one of the last venues Russians have for it. Russian investigative journalists Andrei Soldatov and Irina Borogan reported on that the technology required to enforce the blacklist would give the government the infrastructure it needs to monitor Russian Internet activity on a massive scale, “spying on millions of Russians.” This is a leap in Internet control; not merely bullying Internet service providers or shutting down Web sites, the authorities appear to be moving to dig deeply into the data stream.

Reporters Without Borders points out that the blacklist is only one of many new policies in a broader rollback of Russians’ freedom. The state is curbing the use of technologies to evade Internet censorship and may soon further restrict “blasphemy.” Libel has become a crime. Leaders of the Duma, Russia’s lower house of parliament, promise more to come. Most disturbing, the legislature has voted to redefine “high treason” in a way that would vastly expand the universe of people whom the state could charge, possibly including journalists, activists and others who may be a danger to Mr. Putin’s regime but are no danger to Russia itself.

The crackdown reflects not strength but weakness. Mr. Putin’s return to the presidency for a third term, a rigged parliamentary election and rampant corruption have eroded his legitimacy. Mr. Putin’s response — increased state control — will not advance his standing or his country’s well-being. When he took over the Russian airwaves, he faced little popular pushback. But the blogosphere, Facebook and Facebook-like online social platforms have boomed. Controlling these and other sites will be difficult — already, the Russian Pirate Party is promising to unblock blacklisted Web pages — but the authorities’ attempt to monitor and filter the Web could still push innovative Russians toward the opposition, or out of the country.

The Kremlin is stifling not just Russians’ freedoms, but the country’s economic potential. Silence free speech and steal elections, and corruption flourishes. Restrict the Internet, and high-tech innovation becomes less about improving people’s lives and more about evading the censors. Russia is a country desperate for modernization, political and economic. Mr. Putin’s actions seem to be moving in the other direction on both fronts.