Although South Park's creators are known for producing controversial content, they don't usually say sorry for it.

Late last week, Trey Parker and Matt Stone apologized to the writers of a CollegeHumor.com video after they accidentally copied original content. Although the episode ("Insheeption") incorporated several lines from a clip called "Inception Characters Don't Understand Inception," Stone and Parker said they didn't know what they had done.

In an attempt to do an Inception-based episode, Matt and Trey tried to watch the movie for themselves -- unfortunately, they struck out finding a theater showing or a copy of the film. That is when they came across the College Humor clip (which can be seen after the jump).

“We thought their joke was that a lot of those lines were actually in the movie and they were banging them against each other, and showing that the Inception characters didn’t even know Inception," Stone told the New York Times. "That was a mistake, and it was an honest mistake."

Fortunately, writers Dan Gurewitch and David Young have accepted Stone and Parker's apology. "David and I just got off the phone with Matt Stone (coolest sentence I’ve ever written). He was extremely nice and apologetic," Gurewitch wrote on his blog. "All is well, and we’re going to meet up with Matt and Trey when they’re in New York."