This is pretty old. It started with gamers, so I got RickRolled around the time it began, thanks to my kids (one of whom is a Merciless Warrior in the WoW game.) And I am periodically RickRolled to this day because they think it is funny that I defended Rick. Doubly funny after Uncle Cool told them I had the album and liked the music. Old mom, so lame.
The youth of America thought long and hard over what they might consider the single lamest thing ever in pop culture to toss at you as a jibe. And they selected Rick Astley.
They send you a link to of something that you'll find interesting. Say, your son's college grades. When you click on it, you get "RickRolled" and get Rick singing.
It's like a "Ha-ha! Got ya!" kind of thing. For the kids and I, it is also, "Your taste in music SUCKED!"
Being RickRolled makes me feel old as dirt.