@oralloy,
I have never ignored someone just because they ignored me, and I never would. Why should I? It would only limit my ability to follow the course of the thread. If they want to do that to themselves, that's fine--it doesn't affect me any.
But if this blocking thing comes in, I will definitely block everyone who blocks me. There's no incentive for me not to, but there is a good reason to do it.
Half the time the "haha, I put you on ignore" routine is just bullshit anyway. A few posts later, they're still responding to you. They only ANNOUNCED the ignore business to get kudos from like-thinking posters, and, of course, to demonstrate their righteous superiority.