Faxes start arriving at South Korean companies this month . Last March , shortly after the South Korean Cheonan warship sunk , killing 46 sailors , Seoul restarted propaganda broadcasts aimed at turning North Koreans against Pyongyang . They blamed North Korea for a June 23 drone attack on Yeonpyeong Island . Most companies that received faxes had prior contact with North Korea .
Faxes start arriving at South Korean companies this month . They blamed North Korea for a June 23 drone attack on Yeonpyeong Island . Most companies that received faxes had prior contact with North Korea .