Yes, cable-TV cutting is real.

Even as Comcast and TWC see their internet service subscribers grow, they're also seeing their cable-TV subscriber numbers shrink at a steady rate.  Since Q4-2007 (older data is not easy to come by), Comcast has seen a 11.4% decline in TV subscribers, and TWC a 10.5% decline.  Why focus on Comcast and TWC?  Because they're the two largest cable-TV companies in the US, by wide margins.

Last Summer, GfK Media reported that approximately 21M US households were OTA-only broadcast TV viewers.  If you look at Comcast's just-released Q1-2013 financial report, there are now about the same number of households paying for cable TV via Comcast, as are people across the US using OTA-only broadcast TV.

What's driving this?  Cost, obviously, but also the growth of online video.  If cost alone were the issue, Comcast and TWC wouldn't probably see internet subscriber growth even while their cable-TV numbers shrink.  Online video gives cable-TV cutters some of the content they want, but at a drastically lower price.

For instance, Netflix recently reported that they had added 2 million streaming subscribers in Q1-2013.  Because as many as 10 million people may be watching Netflix without paying, Netflix recently announced plans to allow for up to 4 simultaneous streams from a single account, regardless of your IP address.  So, your college kids could stream movies from their dorm, while you're streaming videos at home.

Meanwhile, Hulu announced that it now has 4 million paid subscribers, doubling year over year.

In other words, quality online video is widely available, relatively cheap and extremely popular, and it's hitting cable-TV subscriptions.

So you have to wonder, what in the world those OTA broadcasters are thinking of, when threatening to drop OTA broadcasts for cable-TV-only access, in their complaint against Aereo.  After all, it's monumentally stupid to climb onto a sinking ship.  It should be obvious that online video subscriptions is the way to go, not cable-TV.