This group was pretty bold openly selling and using drugs at this bar in Mokpo:

Foreign nationals arrested while using drugs at a bar await questioning at Mokpo Coast Guard building in Mokpo, Friday. Yonhap

Over 30 foreign nationals have been arrested in the southwestern port of Mokpo for using methamphetamine during a drug-fueled party at a bar, according to local police, Friday. 

The Mokpo Coast Guard said it raided the pub exclusively for foreigners at 2 a.m., Wednesday, and apprehend 34 foreign nationals ― 24 men and 10 women. It has sought arrest warrants for eight including a 29-year-old Vietnamese national for dealing in narcotics.

The police deployed a special unit to seize a key suspect allegedly known to be the mastermind of a drug ring in South Jeolla Province. A considerable amount of methamphetamines were found during the raid. 

Korea Times

You can read more at the link.