It's an unusual stunt with dire consequences.
Two young men jump onto the tracks at the O-train Bayview station, grab on to the back and take a high-speed ride to Carleton University.
Nothing bad happened to them physically, but now that the video has been posted on Youtube OC Transpo officials say they could be arrested.
The transit company says there is a criminal investigation underway, and it is looking at a variety of charges including mischief and trespassing.
"It's extremely serious and extremely important that people don't try it," says Kimberly Weston-Martin of OC Tranpo.
OC transpo plans on attaching cameras to the train's exterior with a live feed to the conductor and communications centre.
Train-surfing is considered an extreme sport by some young people and is ranked highly beside skydiving and rock climbing.
If the culprits are caught, they face anything from a $600 fine to jail time.
With a report from CTV Ottawa's Joanne Schnurr