Comcast wants to own the internet — or, at least, the cables that carry it to most Americans’ homes. Yesterday, the company laid out its arguments for acquiring Time Warner Cable in a filing with the Federal Communications Commission. The merger, announced in February, would let Comcast take over markets that include, among other places, parts of New York, Texas, and Southern California. This would give Comcast a stranglehold on the US broadband market, but it’s not a sure thing yet.