The laptops are much in demand by officials and students in Pyongsong city, North Korean sources say.
Authorities fear Moon Jae-in may now be favored in popularity over Kim Jong Un, sources say.
A ‘special investigative team’ is deployed to jam and locate the devices during the sensitive meeting.
One analyst said the Pyongyang agreements were "modest but sufficient" to move US-North Korea talks forward.
Authorities tighten security in the capital as talks between Kim Jong Un and South Korean president Moon Jae-in get under way.
The money was taken from cash gifts offered to North Koreans by their South Korean relatives, sources say.
This year's performances highlight the 'long-term' friendship between North Korea and China.
Park Jin Hyuk hacked for North Korea's government or ruling party, the U.S. Treasury Department says.
Many had watched the 2018 Asian Games in Jakarta, in which North Korea placed poorly.