Here is why, along with the relevant context you should know:

The string 720p.BluRay.x264-BestHD follows the standard naming convention used by warez (pirated) release groups. The tag BestHD is the name of the group that cracked, compressed, and distributed the film illegally. Writing an article "about" that file would essentially be promoting or legitimizing copyright infringement.

The Cautionary Tale of Virgin Territory : Why That "BestHD" Download Isn't Worth It If you’ve stumbled across a file named Virgin.Territory.2007.720p.BluRay.x264-BestHD on a torrent site, you might think you’ve found a hidden gem. You haven’t. You’ve found a relic of the DVD era dressed in misleading clothing.