The Russian-language Twitter account of the Russian Prime Minister, Dmitry Medvedev, was apparently hacked today. One of the tweets, now deleted, read I like reading @Navalny in English — a reference to the Yale-educated lawyer and activist Alexei Navalny. The Wall Street Journal has called Navalny the man Vladimir Putin fears most. Around 40 minutes after the first tweets appeared from the hacker, they were deleted.