Mikhail Fishman is an anchor at TV Rain. He is the former editor in chief of Russian Newsweek and Moscow Times. The opinions expressed in this commentary are his own. This is the next installment in the CNN Opinion series on the challenges facing the media, under attack from critics, governments and changing technology.

(CNN) In April 2012, shortly after Vladimir Putin had been re-elected as President and returned to his throne in the Kremlin following a four-year intermission as prime minister, protest demonstrations broke out in the southern Russian city of Astrakhan. A local political activist, who was running for mayor but lost, went on a hunger strike after what he claimed was a totally rigged election. The crowds rallied in the streets in his support, echoing the Bolotnaya Square protest movement in Moscow and St. Petersburg.

I was covering the demonstrations for TV Rain, an independent cable news network that was established in 2010 -- under what was known as then-President Dmitry Medvedev's political thaw -- and got a strong foothold with its exclusive in-depth coverage of Bolotnaya Square protests in Moscow. At that time, millions of Russians had access to TV Rain's channel.

Yet I was surprised when an Astrakhan law enforcement official, who was clamping down on local protests, confided in me that he and his police unit watched TV Rain regularly. Wow, I thought back then, things were going to change quickly because even the police forces were paying attention to independent media.

Things did, indeed, change fast. The protests in Astrakhan were crushed, the Bolotnaya movement was defeated, hundreds of protesters were arrested and the crackdown on civil freedoms was codified with repressive legislation. Eighteen months after I heard the Astrakhan official's confession and a few weeks before the Crimea takeover, TV Rain -- still independent and working opposite to the state's growing ideological pressure and propaganda -- was widely pulled . Private cable television providers unanimously cut it from their list of available channels, under the pretext that they had felt offended by one of the network's onscreen polls about the cost of not surrendering St. Petersburg to the Nazis during World War II.

During the Soviet era, political censorship was an established governmental institution. It had its regulations, procedures, offices and staff. Nowadays, in Putin's Russia, it isn't as conspicuous as it was, but it's still very powerful. It comes in the form of phone calls, hints or nods. Across Russian media, except for two or three publications, an acute self-censoring instinct -- put simply, fear -- is now a commanding feeling.