So why is Rick Rolling a bannable offense?

As I sift through the glorious chaos of the Coaching Changes Board, I'm reminded of how I was banned last year. Admittedly I probably deserved it. As I recall, I came up with the bright idea to troll folks caught up in the Jimbo hysteria. I entitled the post to ostensibly be about a great interview that provided background on why Jimbo loves Louisiana so much.

The link itself was filtered through goo.gl to mask its real location. Which was to land the unsuspecting Rant Poster on a video where a Mr. Astley sings about never giving them up or letting them down.

Like I said, I obviously deserved the trip to banland. But in the dozen or so posts and a few, "You know that you can't link to that video here," I was just starting to wonder why Rick Astley is the bannable offense as well as the purposeful troll on my part?

Does anyone have the backstory about why that video in particular is bannable, and whether there are other auto-ban-land bugaboos the average Ranter may not be aware of besides linking to p0rn, etc?