One of the newest members of the EU, Estonia, says many of its state and commercial websites are under sustained 'denial of service' attack (see here) from servers in Russia which, according to Estonia, are Russian state-controlled servers. Russia denies any involvement.
This apparently relates to a simmering feud between the two countries ostensibly over the relocation of a Soviet war memorial in Tallinn, the Estonian capital.
I think this is just the latest example of Russia, under President Putin (a former KGB operative) attempting to hold other countries to ransom. It is no secret that Russia dislikes intensely the fact that former constituent parts of the old Soviet Union (Estonia, Latvia and Lithuania) have, in their eyes, 'gone over to the enemy' by joining the EU and NATO. Those three countries counter, correctly, that they are simply returning to their rightful places within the mainstream European family of nations. Undoubtedly there will be further examples of the Russian bear's petulance in coming years; I hope the EU supports forcefully Estonia both because it is a member state of the EU and because if it doesn't it will only encourage Russia to further acts of international brigandage.
Of course this whole article is written in the assumption that Russia is behind these attacks. If it is not then I apologise, but I think it highly likely that it is the source. No doubt this will become clearer in coming days.