I've already heard most of the arguments against child pornography, and frankly I don't find any of them any more convincing than the arguments against gay marriage.
Possession of child pornography creates demand and encourages more abuse.
Purchasing it would, which is why it should be illegal. Anonymous download without purchase would not. I'm in favor of legalizing the simple possession of child pornography, not the production, sale, or purchase.
Watching child porn victimizes the child all over again.
This is one of the most common arguments, and one of the weakest. How can someone be hurt by something that happens without their knowledge that will never affect them?
Have you ever fantasized about someone while masturbating, or even thought about someone else while having sex with your partner? A classmate? A co-worker? An ex-lover? A stranger? Maybe you've watched a hidden-camera sex tape or seen someone's home sex videos that they've uploaded to the internet without their lover's knowledge. Consider this. They did not consent to being a part of your sexual fantasy.
You used that person as an unwilling participant for your own sexual gratification. How do you feel about that? Do you think the person was hurt by your actions? Do you feel you should be put in prison for it? Of course not. They have no idea you did it and they were not harmed by it in any way.
Watching child porn will lead to the rape of more children.
Actually, it has been proven that greater access to pornography leads to a decrease in sexual crime. As everyone knows, pornography is an outlet for sexual energy. Since the advent of the internet (and subsequent proliferation of online porn) sex crimes have dropped nationwide. The biggest drops are in states that have the highest percentage of internet access per capita. Prisons which allow inmates to keep pornographic magazines in their cells have lower rates of sexual assaults.
Pedophiles are dangerous and will eventually rape a child.
The thinking here is that sexual attraction leads to rape. That's true. But that's true across all sexual orientations, not limited to pedophiles. Men rape adult women, men rape other men, men rape animals, and men rape children. Rape is present anywhere there are men. That's a fact.
The problem is assuming that all pedophiles will commit rape because they are sexually attracted to children. If you apply that same logic in other situations you immediately see the flaw in it. If that were true, all men who are attracted to women, men, or animals would also eventually commit rape. We simply know this is not the case.
The truth is that the vast majority of pedophiles will never commit rape for the same reason that the vast majority of men will never commit rape. They know it's wrong.