Ask HN: Browser Plugin that filters low quality web pages

Is there a web service which lets you install a plugin that filters "legal" but low quality sites?

Let's say I'm surfing the web, I click on a link in some blog. The link directs me to a low quality web site. By low quality, I mean people (who also have the plugin) have visited that page before I did, and left under 5 seconds or so. Instead of redirecting to the linked page a warning appears and tells me if I really want to visit that page as it seems to have a low quality rating (high bounce rate).

The bounce rates of different web pages are then analyzed and user clients will frequently get updated with webpage quality filter list.

TL;DR: A plugin which is like Xmarks but indexes the pages you (and others) don't like and lets you know if you're about to visit one.

Anyone would care to use a plugin like this?