Happens all the time :) I think it's exaggerated by the automatic upvoting when submitting something that was recently submitted too. So as people discover the

Happens all the time :) I think it's exaggerated by the automatic upvoting when submitting something that was recently submitted too. So as people discover the same thing, they submit it to HN and each submission upvotes the first submission. We're all discovering the same things seemingly :)