Complex sentence: Although it was an important development for the Web, BitTorrent was widely considered to be the bane of the film industry, because it made the Web cost effective for large file distribution--in many cases BitTorrent was used for distribution of pirated movies and TV.
Split into simpler sentences: Although it was an important development for the Web, BitTorrent was widely considered to be the bane of the film industry, because it made the Web cost effective for large file distribution. In many cases BitTorrent was used for distribution of pirated movies and TV.