Not useless, will make people be afraid that in the future they do arrest people or cut the fiat-BTC channel, so people will avoid invest in Bitcoins and the adoption will stop.
But still though, even though citizens of Russia won't be able to cash out so easily on their ISP's to bitstamp or something like that... they can still sell locally at at localbtc, as seen in the OP's pictures... Also they can easily get VPN's or maybe run through Tor to get on bitstamp. It's really not (or shouldn't be seen as) that big of a deal.
While we're on the subject, I think we all knew that North Korea has blocked bitcoin exchanges lol... hell they've, in a way, blocked "food". There are starving people in North Korea, I don't think they are too worried about exchanging some bitcoins.