Park Jeonggeun, a political activist, re-tweeted the message "Long live Kim Jong-il" from the communist country's official Twitter account. He said he intended to ridicule the leader, who died in December, but could face up to seven years in jail. Amnesty accused South Korea of "failing to understand sarcasm". "Imprisoning anyone for peaceful expression of their opinions violates international law, but in this case the charges against Park Jeonggeun are simply ludicrous and should be dropped immediately," said Sam Zarifi, Amnesty's Asia-Pacific director. Mr Park is a member of the South Korean Socialist Party, which openly and frequently criticises the North Korean regime.