It was their will to capture scandalous moment inside the bathroom when they made it inside. He was with girlfriend when their parents left. It was seen on the video that they are already not wearing anything aside from towel when they entered the room.
The person who uploaded it claimed to have an access in the live view via internet. He is also allegedly responsible for sharing a copy.
Netizens now are thankful for knowing precautions like this. It will always be best to ask for protection whenever using any IP cameras. Make sure to be the only person who have access on it.