While the video doesn't appear to be recent, Canadian officials are still taking it seriously. They believe it was taken at British Columbia's Tuchodi Lakes last July and have launched an investigation into the incident.
Wildlife harassment is dangerous to both animals and humans. There's no doubt that the moose was stressed by the incident, and could have been harmed by someone jumping on her back from such a height. Moose are also quite capable of injuring or even killing a human.
David Vince, a member of British Columbia's Conservation Officer Service, told the New York Daily News that the perpetrators could face fines of up to $200,000 Canadian dollars once found.