The founder of Russia's equivalent to Facebook, VKontakte (VK), has resigned as CEO of the company after seven years.
Pavel Durov said that he could no longer "stick to the principles" of freedom and independence that he believed in.
The move had been expected as the 29 year old had flogged his 12 percent holding in the firm in January to Ivan Tavrin, chief executive of Russian mobile phone operator Megafon, at an estimated value of $420 million.
Megafon is co-owned by Russia's richest oligarch, Alisher Usmanov, who is a close chum of President Vladimir Putin.
Writing in his bog, Durov said he had less freedom in managing the company after the changes occurred in the Vkontakte shareholders' structure in April 2013.
The farewell letter included the picture of the dolphins from Hitchhikers Guide to the Galaxy, saying "so long and thanks for all the fish".
VK is the second most popular social network in Europe, with a particularly strong following in Russia, Ukraine and Belarus. It has around 200 million accounts and 45 million daily average users - compared to over one billion accounts and 665 million daily users for Facebook.
Durov is known as an eccentric libertarian in start-up and left-wing groups. He made £170 million prior to selling his stake in the company.
However it all started to go pear shaped in 2011 when protests against the Kremlin exploded in the streets amid allegations of election-rigging. Putin's allies demanded that Durov to shut down VK pages operated by activists.
When he refused there was a police raid on Durov's home and he ended up charged with driving a white Mercedes over the foot of a traffic cop.
He denied any wrongdoing but fled the country before police could arrest him. After the raid, two VK co-founders decided to sell their 48 percent stake to United Capital Partners (UCP), an investment firm managed by Ilya Sherbovich, who is believed to be close to Putin.
Since then, Sherbovich slammed Durov's actions accusing him of using VK resources to promote the instant messenger Telegram, a Berlin-based firm that he funds.