Park Jong-soo played all 90 minutes in South Korea's 2-0 win over Japan in Friday's bronze medal game. As he walked off the field he held up the sign you see, which apparently reads "Dokdo is our territory." The reference is to a group of islands between South Korea and Japan in waters (the Sea of Japan, or the East Sea...or the Korea East Sea depending on your perspective) rich with natural resources. Both South Korea and Japan claim sovereignty over the islands.
His protest came hours after South Korea's president, Lee Myung-bak, paid a surprise visit to the islands. The visit infuriated Japan, which withdrew its ambassador from Seoul in protest.
Personally, I would have thrown some good ol' scare quotes around "protest," but I don't work for The Times. Anyway, the holding of a sign was determined to be a political statement and all the governing bodies of Soccer, with their strict anti-political statements/pro-political corruption stance, got pissed and will hold their own investigations. London Olympics officials asked that South Korea handle this mess and South Korea decided to keep Park off the podium while the rest of his teammates received their medals.
South Korean Denied Medal Over Politics [New York Times]