But here is it in basics:
Russian opposition was completely dominating the Internet at the time, before around 2005, a complete opposite of the picture on the TV, and fake opinion polls.
Kremlin was not happy, and went straight to the Internet's "kingmaker" — Google (or maybe it was the other way around?) Publicly it was to get its officers "taught" about internet media, but the writing on the wall was way more obvious.
At around late 2005, Google announces them "optimising their algorithms against abuse," and within weeks opposition's websites start to disappear from Google one after another. Google obviously claim "we did not hardcode anything," but simply rearranging the word order in search was enough to expose them doing that.
At the same time, we saw a wave of very weird adsense political ads on sites associated with opposition, and a wave of exhilarating pro-Putin drivel in Western media, clearly suggesting they got some Western spin masters on their side now.
In my personal experience Meduza articles are near the top for some topics and several years ago Dozhd was popular as well, also sometimes I get links to opposition LJ blogs. Also there was a large shift to Telegram channels from traditional websites.