Statutes are on a per State codification; which in "Carrier" terms regards the sale of their channel. Each market is defined to be per each States, City, County; which is based today on population centers that a channel serves. So, if ABC broadcasts their channel locally; to say a Los Angeles area, this channels revenue and tax basis resides there, and is taxed there. If this market channel was say, KTLA, an independent channel, and part of a "Superstation pak"; those revenues derived outside of its locally broadcast market would be taxed upon receipt to each market it supplies itself to (revenue from/to another "city, county, state"). This gobblygoop of a tax base, depends on where "business" takes place; and what the channel wants is only to be taxed in the State it resides in; rather than to share such monies with other States. They want to keep their monies derived in sales of/within other States, like everybody else does by "internet" typed transactions. The States the channel is found in/broadcast to; then lose any "local" flavor of the transactions; like normal commerce is doing today.
However, ABC has many local broadcast's; and each market they serve and receive revenue from, is local; where as KTLA or any Superstation and others, uses "carriers" in the "states". One would believe it means the same thing, but advertising nationally without paying the other states is why they put this "copyright" in for Nationally progressed channels. The portion that comes out as tax, local or national, where and what basis a channel should be held as; is what the law is addressing. It looks to be a "taxing" situation no matter what the; channels want to go "national" like syndication, which allows a certain type of program to be broadcast by anybody, as long as they get their fee; the letter of the law against "Copyright" would say that anybody can broadcast anywhere anything, including locals on National; and a local station going National, butting heads up against many other laws "copyright" law was put in to place to protect; rights of channels to their own broadcast area; which a signal "is"...
in Law