According to a Yonhap story entitled "Lee Gun-hyeon: 'Native speaking English teacher crime [is] serious'", the National Assembly’s Council of Education, Science and Technology member Lee Gun-hyeon of the GNP announced on September 24 the number of native speaking English teachers who have committed crimes over the past three years. Over three years the total is 274, with 114 in 2007, 99 in 2008, and 61 up to August of this year.
By type, at 84, most were arrested for violence, 57 for drugs, 17 for ‘intellectual crimes’ (likely forgery), 10 for rape, and 7 for theft. As for violence, cases had risen from 22 in 2007, 38 in 2008, and 24 to August this year.
By region, 138 teachers committed crimes in Seoul, 29 in Busan, and 17 in both Gwangju and Daegu.
Throughout the country, in 1,100 elementary, middle and high schools are some 7000 native speaking English instructors, and in hagwons there are about 20,000 . [Note – someone is not doing their math correctly or are using the wrong statistics. There are only about 20,000 E-2 visa holders in the country (which is the group I assume they are referring to)]
Lee said that recent crimes by foreign English teachers are causing students and parents’ anxiety to grow and that the verification system for unqualified foreign teachers needs to be strengthened and criminal information made public and that students should not be exposed to more crimes.
[I should probably note that this hasn't attracted that much attention. Naver only shows four different articles referring to it, most just reprinting Yonhap.]