Starbucks Korea’s “Tank Day” controversy shows how quickly a marketing campaign can become a legal, contractual and governance problem when ignorance, insensitivity or weak internal controls collide with South Korea’s polarized historical memory.

The promotion ran on May 18, the anniversary of the 1980 Gwangju Democratization Movement, when soldiers violently crushed pro-democracy protests.

The promotion also used the slogan “slap on the desk (책상에 탁),” a phrase many Koreans associate with the false explanation police officers gave in 1987 to explain the death of Park Jong-chul, a student activist, whom it was later revealed to have been tortured to death.