Actually, it would be far, far easier to steal another, less-well secured bike. That's the point.
I've heard variations of that story for 40+ years, with locations indicated all over the world. 18 bikes @ ~25# ea + the weight of a 20+ bike bikerack in mild steel is going to be on the order of 700 pounds - each of the four guys is going to be lifting ~175 pounds up into the back of a flatbed truck with the bikes flopping and snagging all the way. Hmm. Don't suppose your student newspaper covered this story with pictures?
It was covered in the Student paper, and the college went and put some sort of bolts in that could not be undone with commonly found tools. I know this happened, I was attending the college when it happened, I read about it in the paper, and because the guy got busted about a 3 months later, and they found over 100 stolen bikes in his barn, he had been selling stolen bikes for years before he got caught. The really weird thing is he only served 5 years in jail, and when he got out he opened a bike shop?!