Other than sex addicts, most of what I say applies only to fellow christians, since we are mainly the only ones who try not to indulge in it. And struggle we do. I once, in college, went an entire year without masturbating, and have never again been able to even approach replicating the feat. Some don't see a problem with masturbation, and perhaps if it were entirely disconnected from porn it might be ok, but it is not; indeed it is intricately linked with all manner of sexual thought, to the extent that I do not believe they can ever be truly split. I look at porn, I masturbate. I want to masturbate, I usually look for something to arouse me.
I still vividly recall my college Young Life leader telling our guys group that porn is false intimacy. Many times now I have thought on how true that is. A lot of us medicate with porn, be it by image, photo, drawing, movie, or game. Loneliness and boredom are a nasty combination, and porn offers the idea of the perfect man/woman who is always there, always willing, doesn't judge, and doesn't require anything. How many of us long for that perfect someone who accepts us for us? And she is never not in the mood, never intrusive, never questioning. Pity it turns out to be so hollow.
But hollow it very much is. God made us to work a specific way. He said that it was not good for a man to be alone, made a woman, and together they are to become one flesh. It is to be a mirror of Christ and his church. Porn, at best, is uniting a man to himself in sinful gratification; at worst it is idolatry and adultery both. It is placing the idea of sexual pleasure above all else, as the utmost in importance. Porn allows us to commit adultery on scale that defies belief.
And that's not even addressing the physical, emotional, mental, and relational fallout. Is there honestly anyone who catches their loved one with porn and doesn't feel anger, grief, and hurt? It feels like betrayal, and it is. They are saying, in brief, that when compared with yourself, you are the one lacking. Porn destroys relationships, creates unrealistic and unhealthy expectations, and usually treats women as merely an object to get off to. I've seen a handful of animé (hentai) that treat women as equally important, but I don't think I've ever seen the like in our stuff. It's always some scary meathead with a disturbingly thick neck and red face being serviced by the woman or women, as if she's some willing slave. When he does bother to do anything, it's usually really aggressive and demeaning.
Watching such things also effect how we view the world. How many guys I have spoken with who, because they watch so much porn, see it everywhere they go, mentally undressing and screwing every pretty girl they see, whether they want to or not. That episode of Friends where Joe and Chandler get free porn is actually fairly accurate. That hot banker wants you, that pizza delivery girl is totally asking for it, that lady on the street wants you to bend her over...Bleck. I tend to notice faces more than anything, but if I have been lately sinning with porn frequently, I start to mentally x-ray before I can catch myself. Lust begets lust.
I don't want to treat women like objects, and I neither want them to be so treated, nor to offer themselves up as objects. Sometimes, in those rare moments of sanity when I am trawling the net for naked women to ogle (assuming I'm looking at a real one and not animated), look at all these absolutely lovely, stunningly beautiful women baring themselves for everyone to see and masturbate to, and want to cry. These things should be private, between a husband and wife only. A wife's body should be a special gift for her husband, and vice-versa. On the surface, I am aroused, but inwardly I desperately long to tell them that they are worth more than that. If I see you naked, I want it to be just for me, and I want all of you: mind, heart, soul, and body.
The reason porn is hollow is that it is one-sided. There is no give, no love, no true interaction between equals, just take, take, take. You are here to pleasure me; who cares about you. Porn in the male community is like heroin or meth. Every hit is poison, and even as we indulge we know that it is toxic. Some don't care at all, some a little, and some of us try our best to get healthy.
I know there's more rattling around up there, but that's all I can think of at present. I welcome any questions or thoughts on the matter. Better to be an open book with no secrets. Sin abhors the light, after all.