On a frosty Canadian morning, a masked crusader tromps across a parking lot, over a snow bank and onto the sidewalk. He has a loudspeaker strapped ominously to his chest.

He halts, aiming the speaker toward the building across the street. "This is a song by some dead guy," he says. And then, music booms forth:

"Never gonna give you up, never gonna let you down, never gonna run around and desert you."

It's an anti-Scientology protest, and across the street, a dozen or so warmly dressed young people begin to dance and sing along, waving their picket signs in rhythm to the familiar tune.

"It's a bit spooky, innit?" said Rick Astley, the singer who made the song famous in 1987 and who is not dead.

Over the last year or so, Astley has watched with puzzled amazement as "Never Gonna Give You Up" has been mocked, celebrated, remixed and reprised, its original music video viewed millions of times on YouTube, all by a generation that could barely swallow its Gerber carrots when the song first topped the pop charts.

"I think it's just one of those odd things where something gets picked up and people run with it," Astley said. "But that's what's brilliant about the Internet."

Search for Astley's name on YouTube and you'll find dozens of instances of the campy, infectious video, which features a heavily coiffed Astley bobbing and swaying behind oversized sunglasses. He's flanked by two blond backup dancers (one of whom apparently didn't have the footwork down), and a male bartender in short shorts who excels at spontaneous back flips.

Rickrolling is an example of an Internet "meme" (defined by Wikipedia as "any unit of cultural information ... that gets transmitted verbally or by repeated action from one mind to another").

With all the online momentum it's gathered, the Rickroll has now trundled its way into the real world, too.

See The New York Mets Get RICK ROLLED

Why have people picked up on the song so much? It has just turned out to be one of those viral phenomenons.