I've encountered something similar a couple of months ago. Was heading towards Malacca with 3 of my friends when we decided to have lunch over at the Seremban rest station before resuming our journey. After lunch, we were heading back towards our car when a bunch of teenagers approached and offered us a bunch of N95's. We just ignored them and proceeded to our car. The bunch of them followed us and began swearing and shouting at us because we weren't entertaining them. This continued even after we got into the car. Thank God they did us no physical harm. Was pretty shaken. But it was a weekday when we went and the rest station then was pretty empty. My advice to those who travel : Try choosing a rest station with more people when you travel, especially during non peak hours. And be extra vigilant!