I was going to say that there are several Firefox plugins to check links on the page for you, but the ones that I took a cursory glance at look like they could

I was going to say that there are several Firefox plugins to check links on the page for you, but the ones that I took a cursory glance at look like they could really slow down your browsing, or automatically "click" on links (like Delete or Upvote/Downvote) that you really don't want them to click. So I see now that this problem is indeed a little more complicated then that. What we really need is a plugin that makes a quick query to a central service every time you hit a page and checks to see if anyone else has "reported" bad links on that page, and if they have it will highlight them or cross them out for you. Or it could send a list of all of the links on a page to the server and check them against the servers bad links list. Other than that it will let you do your own thing until you hit a bad link on a page, at which time it will look back at your history and see what page the bad link exists on and "report" that bad link/page to the central server so that any other user that hits that page will know before they click that that particular link is bad. There would be, of course, numerous privacy concerns, but I think that if a company was willing to really "do no evil" and could garner enough user support to make it effective this could turn out to be really helpful. Thoughts?