I feel this should be a browser feature rather than having a website. One has to search for the book mark and then provide email id, enter the captcha. Instead

I feel this should be a browser feature rather than having a website. One has to search for the book mark and then provide email id, enter the captcha. Instead of these whenever there is HTTP 404, browser itself can give a icon in the address bar to keep polling the website. Firefox plugin may be?