> does it really matter how many times something is reposted, as long as it gets upvotes

It fragments the discussion.

Perhaps the dup checker might profitably ignore fragments, since it seems like Medium isn't the only site that perverts them.

They all seem to have URLs with random-looking fragment identifiers at the end, which I guess makes HN think they're unique.

Due to some weird rule, you can't submit the same URL again, in this case, the unique hash is different if you look at the URL.

I've been using http://hckrnews.com/ , it's a convenient site that shows every story that hits HN front page. It's a good way to small catch stories and also controversial ones before they get flagged.