Further to our brief conversation a few weeks ago, I failed to express my main point, which is that it is wrong to initiate violence against someone who isn't physically molesting a child (or anyone else). Merely consuming child pornography or other distasteful images or ideas is not physical harm, and so cannot rightfully be stopped or punished with main force. We can disapprove, but we are not morally entitled to inflict violence on those who aren't actually molesting children.
You say the consumption of porn amounts to demand which leads to physical molestation, but this link is indirect and questionable. For example, a person consuming secondhand porn would not translate into demand for porn production.
Even a pedophile (contrast with pederast) who pays a child-pornographer is only providing an incentive to do evil; the actual evil is entirely the responsibility of the molester himself (in my view--I'm not sure I can prove it at this point). Paying him does not diminish his culpability. The point in this paragraph might be seen as dubious and/or unconvincing; I admit it is a personal view about the responsibility of evil that I have been developing myself. Another example of my idea is that the greater blame for crimes such as the Holocaust rests with those who actually committed them; Hitler was clearly a raving lunatic with a juvenile worldview to whom no one should have listened, just as no rational person would carry out the bidding of a ranting child.