Lalonde was recording himself lifting 350 pounds, when the noise of the weights hitting the ground drove one fellow patron over the edge.
The man approaches Lalonde, before kicking the barbell from his hands, shouting, "Get out!" and roughing him up a bit.
We all get peeved at guys for grunting or dropping their weights at the gym, but this was definitely not the way to properly handle it.
You will even notice Lalonde was taking precautions to minimize noise, like placing matts underneath the weights.
Lalonde sent the video to his trainer Pete Rubish, who posted it on YouTube, where it promptly went viral and has since garnered over 3.3 million views.
"I think it came down to the guy picking on someone he thought would be an easy target," Rubish told the Montreal Gazette of why the video caught so much attention
"I think that's what sparked the outrage. It's a classic example of someone not picking on someone his own size."
The man has since been banned from the gym, and an employee has also been suspended for failing to intervene. Lalonde was offered a free membership but declined the offer.
Watch the insane video above, and check out some reactions here.