a) One can also use referer to check whether a visitor has come from Google to trigger the deletion (in addition to "seek itself in Google"). b) robots.txt sha

a) One can also use referer to check whether a visitor has come from Google to trigger the deletion (in addition to "seek itself in Google"). b) robots.txt shall get the same results, plus, no cached content at Google, unlike "deleting itself", which the cache content remains at Google.