“NO MATTER how you kick and squirm, you are a slaughterer”. This was the tweet heard round South Korea last week, as tapped out by an actress-activist, Kim Yeo-jin, who thus set off a particularly undignified row. Not for the first time, the power of social media laid bare the intensely divided state of politics here. As well, it demonstrated the more universal mania that drives people given enough rope to hang themselves.

Miss Kim was referring to South Korea's erstwhile dictator Chun Doo-hwan, on the anniversary of the Gwangju massacre of May 18th, 1980. General Chun, who seized power in the whirl of uncertainty created by the assassination of President Park Chung-hee in 1979, was eventually prosecuted over Gwangju and other misdeeds undertaken during his rule, following the restoration of democracy. In 1996 he was convicted, and sentenced to death. To top it off, he was later released by President Kim Young-sam, in a gesture of national unity, and now lives under constant protection in the leafy Yeonhee-dong district of Seoul.

General Chun is apparently not without his defenders, even today. In response to Miss Kim's message, Park Yong-mo—a minor figure on the ruling Grand National Party's advisory committee—shot back with an astonishingly blunt stream of invective. His first reply read simply, “crazy bitch!” As if that were not enough, he went on to make rather ungentlemanly reference to her looks: “if you're ugly, shouldn't you shut your mouth?”

Mr Park, who was subsequently forced to resign, was not yet finished: he suggested that the true “slaughterers” among South Korea's presidents (cf. the transcript of Miss Kim's original tweet) were Kim Dae-jung and Kim Young-sam, who “killed the economy”. Mr Park is a man not easily satisfied. His eventual statement of apology was addressed to “everyone except Kim Yeo-jin”.

Thankfully few in South Korean politics are so unpleasant and misogynistic as Mr Park. But with the jostling for position ahead of next year's presidential election now moving up a gear, Korean politicians would do well to heed David Cameron's (slightly profane) Twitter-related advice.