David Cameron cracks down on online pornography

Interesting point. People want to look at porn, yet keep it a secret. Why? If there is nothing wrong with it then why should someone care?

Are teachers not allowed to look at porn? Why not? Can porn use be used against a husband in a divorce case? How?

You are making is sound like porn can be something unhealthy or negative? If it was not unhealthy and nothing negative was caused by it - then why these examples?

It almost sounds like you are making a case of why people should have a tool to keep it out of their homes. Why should people have to hide the fact that they want to look at porn?

Everyone of course already knows the answer. Porn can and does have negative consequences (of varying degrees) for most. Therefore, it is taboo in society. Everyone knows that the porn industry exploits women. It uses and abuses them. It is derogatory toward them. You see things like "barely legal" posted all over porn ads. So many men view porn, and they all try to come up with reasons that it is good and healthy - but everyone knows deep down that it is not. The pathetic industry will fight tooth and nail against any kind of legislation opposing it. They will cite freedom of speech and every other possible interpretation of anything they can get their hands on but these losers really just are all about money. They don't care about the lives they ruin. Men are still in power and ultimately give the industry the nod - not because they are doing the right thing, but because they are hooked and guilty themselves so they allow the false justifications to continue.

Porn is a devil - Everyone knows it at some level.

My mention of "life before porn" was not meant to be an argument that port is bad. Some comments here treat port as such a healthy, natural and helpful thing. Lets take the last 100 years of western civilization. the first without porn, the second with. What did it improve? It is hard to argue that it has benefited society as a whole, but not so hard to make an argument that it has harmed it.

And you lose the ability to talk about probability in a meaningful way.

If something does create an almost unprecedentedly large response in the brain, does that make it more likely to create lasting effects in the brain and cause the formation of new neural pathways?

I don't know. You want to claim that it's highly probable but you've provided no evidence for this. I know that porn addicts brains are different, primarily in terms of the reward system in ways similar to other addictions I believe, but you'd expect that to be the case. And you've certainly not linked any probability of large responses to the probability of potential changes to the probability of any potential to harm.

If you can't put numbers on it to compare it to other things, you really have no way to talk about probability that's not just waving your hands around and going 'Look at the brain scan!' Well, so what? Even assuming that all of your premises are true, (and the probability of concurrent events is the sum of their multiples so you've lost probability at every stage whatever the actual numbers would turn out to be; complexity penalty) and these brain scans actually exist, what does that mean? Is the probability of harm five times as likely as something else, twenty? If the initial chance of harm is quite small this doesn't make much difference. Is it three orders of magnitude out?

Neurology is a complicated area of inquiry, unless you know how often a given change links up with some result, it's just a picture.

You can't forget about psychology and stats and still meaningfully make statements like 'it's not even on the same chart' you have to know where both things are to be able to talk about that sort of thing - you have to have put the work in and have the numbers.