Four in 10 foreigners who illegally stayed in South Korea last year entered the country without visas and stayed beyond the visa-free period, data from the justice ministry showed Saturday. The number of illegal aliens in South Korea came to 423,675 as of the end of last year, accounting for 16.9 percent of the total foreigners staying in the nation, according to the data cited by Rep. Song Seong-jun of the ruling Pe...