It's never wise to wander parts of foreign towns that might not be entirely safe.
Alexander Hennessy, however, seems like a fearless traveler.
Still, wandering through the La Boca district of Buenos Aires on his bike may not have been the best idea. For he was accosted by a man on a motor bike who rather fancied owning some of what was Hennessy's.
The accoster had the balance of power in his favor. He had a gun.
The fact that Hennessy lived to tell the tale shows that the gun was never used. But the GoPro attached to Hennessy preserved what was clearly a terrifying episode for the more than 5 million YouTube viewers who have already experienced it.
The whole thing unfolds with an unreasonable matter-of-factness. At first Hennessy thinks the man merely annoying. At the sight of the gun and the demand for his backpack, things turn a touch more serious.
It doesn't matter how many times you say "amigo" -- and Hennessy says it a lot -- it doesn't automatically make a man with a gun your friend.
Why the attempted robber didn't use his gun isn't clear. What is clear is that no passers-by were inclined to help too much until the threat had passed. Hennessy dropped his bike and ran. He was finally helped toward a policeman.
His trip is part of the Global Degree community online video series. On its Facebook page, Global Degree said: "The footage was given to the police and the robber was arrested later that day."
He's now a very famous robber. Famously unsuccessful too, it seems.