We will likely release some of these restrictions as our trust in our child and their recognition of the problem sinks in over the next few weeks. I would never consider an outright ban or prohibition because I agree it does have some of the affects you mention. Instead, this is a resetting of expectations for our child around what level of risk is acceptable.
I remember being in IRC chatrooms and having predators galore trying to get me to hang out with them. From my understanding, the problem hasn't gotten any better.
A parent would be smart to limit some internet access to their children. We ID at bars and brothels (where legal), the way I see it, the day my son is willing to learn to jump through hoops to access pornography is the day he is ready to watch pornography. I'm not all too concerned about them working around these things, but I'm concerned about easy unrestricted access.