Hugh Pickens writes "Big cable companies like Comcast and Time Warner Cable keep saying they don't see Web video cutting into their business, but there's at least one big, dirty exception. Time Warner Cable said in its quarterly earnings report that its video-on-demand (VOD) business dropped significantly in the last quarter. Asked to explain where the drop came from, CEO Glenn Britt came clean, more or less: much of the drop is because, instead of renting a porn video in HD for $9.98, Time Warner's customers are getting their porn fix on the internet for free. 'One of the things going on with VOD is that there's been fairly steady trends over some time period now for adult to go down, largely because there's that kind of material available on the Internet for free,' says Britt. 'And that's pretty high margin.' To be fair, drooping porn rentals don't account for all of Time Warner Cable's VOD decline. Chief Financial Officer Rob Marcus said that while 'the biggest piece of the year-over-year decline was in fact in the adult category,' the rest of the drop is because there weren't many big pay-per-view events like boxing matches last quarter, and because regular movie rentals are down, too."