Are you sure you want to liquidate this item purchased from iTunes?

Got this as loot and got this warning when wanting to sell it. I have never bought weapons or armor from the iTunes. Is this a bug or is it just on a list of things that are possible to buy and thus showing the warning?

http://www.the-innercircle.com/setec..._chain_bug.jpg

Had the same thing with 2 items I had the first day. I think its because these items are also sold on the itunes store, which means since some people are using real $.99 to purchase these items there is a pop up notification to make SURE you want to delete the item.