From Talking Points Memo: According to NBC News, which cited a report in a Chinese newspaper, Jang Song Thaek and five of his closest aides were stripped of their clothes, tossed in a cage and eaten alive by a pack of 120 hungry dogs. The dogs had reportedly been starved for five days.
Jang was considered to be the young North Korean leader's second-in-command.
According to the [Singapore] Straits Times, Jang's alleged treason stemmed from his close ties with Beijing and that the execution has sparked tension between Kim and the Chinese government.
[they just posted this on the main page, but i'd already done the work of writing that headline and finding this image, so i'm posting it here anyway. /tantrum]