You're using a website (hacker news) which has a copyright and privacy policy. When you use this website, you accept this policy and I'm free to read your posts.
If you want to instead post your content to your own website, with a clearly stated policy that excludes people who don't agree with your views on copyright, I'll be more than happy not to visit that website :)
Actually, now that I checked, they don't have one. They apply the DMCA though, so if you think that my reading your comments here is violating your IP rights, you can ask them to take those comments down:
Regarding ad-supported websites, they have their copyright policies and you should respect them (if you care about having their rights respected as much as you care having your rights respected, of course). If you choose not to respect them, it's your free choice to do so and bear any possible consequences - as it is my choice when I don't respect copyright laws, which happens frequently enough, but with my full knowledge that I'm actually violating the rights of the original content creators, and also, in that case, breaking some laws...
[1] If a reader comments on my blog, does she license the rights to me?
When a person enters comments on a blog for the purpose of public display, he is probably giving an implied license at least for that display and the incidental copying that goes along with it. If you want to make things clearer, you can add a Creative Commons license to your blog's comment post page and a statement that by posting comments, writers agree to license them under it.
If a reader comments on my blog, does she license the rights to me?
Surely an implicit license for HN to redistribute the comment exists, but without an explicit TOS, I don't see why it would be irrevocable. So I'd say people disagreeing with my post are still infringing on its copyright.
They apply the DMCA though, so if you think that my reading your comments here is violating your IP rights, you can ask them to take those comments down
Yes, I know, but the DMCA doesn't eliminate the infringement by the users of a site, it just puts the site itself in a safe harbor.
Regarding ad-supported websites, they have their copyright policies and you should respect them (if you care about having their rights respected as much as you care having your rights respected, of course). If you choose not to respect them, it's your free choice to do so and bear any possible consequences - as it is my choice when I don't respect copyright laws, which happens frequently enough, but with my full knowledge that I'm actually violating the rights of the original content creators, and also, in that case, breaking some laws...
Sure, that's the legal position, no argument there. But I think the discussion regards the ethical position.
Regarding ethics, my position is that authors should have the choice to monetize their content with ads if that's their best option.
When this happens, others can make the choice to hack the system and access the content bypassing the ad delivery system, but in that case they should at least be aware that they're getting value from the author's effort without compensating him or her, the ethics of which I'll leave for you to judge case by case.
If you want to instead post your content to your own website, with a clearly stated policy that excludes people who don't agree with your views on copyright, I'll be more than happy not to visit that website :)