On 15 August 2017, two anti-mining activists, Sebastian Hutabarat (47) and Johannes Marbun (37) were attacked by group of people affiliated with stone mining activity in Silimalombu Village, Onanrunggu sub-District, Samosir Regency. Because of the attack, the two men who often raising their voice for saving the environment in Toba Lake area, suffered wound in the face, head, and hands. Two of them had submitted report to the police station in Samosir on the same day, after previously having medical check-up in a hospital nearby.