There are reports that the Ukrainian news website tsn.ua is being blocked by UK broadband providers. Having taken a quick peek it looks much more likely that the issue is actually a routing issue, and a Russian network actually blocking traffic to the site, rather than UK providers acting on orders from those in power.
Usually when the filtering systems block a site, the IP address returned for a website is altered to take people to the providers blocking warning portal, but in the case of tsn.ua the correct IP address is still returned. This is definitely the case with Sky, and the observed route to tsn breaks on a Russian traffic link, other providers appear to use an alternate route.
The problem facing the Government is almost one of its own making, particularly as many see a creep of censorship across the Internet and recent coverage of the proposed blocking of extremism websites will have many assuming that any web page that fails to load was blocked.
The wider question really is how do you square the levels of filtering that is both optional and not optional in a country that is a member of the EU which has just voted to stop providers discriminating against competitors, e.g. mobile operator blocking Skype traffic.