HN Feature Idea: Add the ability to ignore particular users.

Over the last 18 months or so, I've started making liberal use of the "ignore" functionality possible in IRC software, forums, social networks, etc. I've noticed a marked increase in my own happiness as a result. Given the widespread belief that the quality of HN comments has gone downhill over the last year or more, perhaps adding the ability for individual users to ignore particular users who post less-than-helpful comments would be a good idea? I'm imagining an "ignore" link accessible when you click on their username to view their profile page. This would prevent the link from being accidentally clicked. I suppose someone could also create a Chrome extension to do it via JavaScript (hint hint).