Dvd rental availability mystery

I watched Lebanon, PA last night, thought it was very good. I was able to rent it from Netflix, but, interestingly, it is not available for rent at Blockbuster, either online or at any of our local BB stores. However, it is available for download or purchase from BB online. Since there is a controversial theme in the movie, I wonder if BB anticipates discs would be damaged if they sent them out? Anyone heard of anything like this happening with the rental discs of other films?