If the US government controls it, we can kiss our internet rights good bye the moment someone stands up and shouts "won't someone think of the children".
The problem here is that the government has the legal authority now. All that has to happen is someone says "won't someone think of the children." All your research has shown that they haven't used it to target adult pornography, not that they can't. If the government subsidized it, it would be the same (they still can, not that they would).