ATT knows that it can’t beat over-the-top content providers such as Netflix and Amazon, so it figures it might as well join them. ATT announced on Tuesday that it has joined with the Chernin Group media holding company to invest $500 million in a new venture that will “acquire, invest in and launch over-the-top (OTT) video services.” This is particularly interesting because it’s the first time we’ve really seen a company that offers pay TV services make this kind of big investment in over-the-top video. Cable companies such as Comcast and Time Warner Cable have traditionally done their best to wall off live cable TV programs from the Internet, but the popularity of over-the-top services such as Netflix, Hulu and