Since the mods won't blacklist this, let's all upvote it to the front page, so that the dupe detector on the submit page will stop the next thirteen submissions over the next three days…
Most of them have been flagged and thus deleted, but you can see that it's just constant, although infrequent:
https://hn.algolia.com/?query=Y%20Combinator:%20Bookmarklet&...
Just flag it and move on.