WARNING: If you hear a chopper outside covering a massive bike race near your house, TAKE THE WEED PLANTS OFF THE ROOF!!!
That's the lesson some poor marijuana enthusiast in Spain learned the hard way ... when his rooftop weed farm was exposed on live TV.
It all went down during the Vuelta a Espana race on Saturday ... when a TV crew helicopter was following the cyclists as they raced through Barcelona.
At one point, you can see a rooftop with a BUNCH of green plants ... and someone decided to snitch to the cops that it looks like pot.