Guy scrolling through his phone completely oblivious to man clinging to the outside of a train

Okay, so this has to be the silliest thing you could do on a train.

Yes, worse than opening a can of tuna in rush hour.

It’s a bloke holding on to the side of the train as it speeds through the New York City subway system.

It came to our attention via Matthew Beary, who was just sitting inside the train watching in amazement.

MORE: People reckon this cat looks like it has a human face

He filmed the whole thing, posting to his Instagram account on Sunday.

“Classic NYC craziness,” he said.

By Tuesday morning the original clip had clocked up more than 12,000 views on Instagram and spread to viral sites like the New York Post.

“I just wanted to take the video because I thought it was awesome and also scary as hell,” he told New York journo Ben Feuerherd.

“Why would anyone ever do that?

“It seems like the most unsafe way to ride the train.”

MORE: Thieves destroy servo shopfront while trying to rip out an ATM

But while the train surfer copped a lot of attention online, he went pretty much unnoticed at the train station.

One passenger, so engrossed in his phone, doesn’t even seem to be aware he’s less than a metre away from a bloke risking his life for a stupid stunt. 

Thankfully, the train surfer stepped away unhurt, but the video could have ended very, very badly