Duplicate Content nicely moving up at Digg

As usual I was digging the most interesting stories on the tech category page, what strikes me a duplicate entry which has the same heading, pointing to same link, submitted the same time, and more shocked to see that both the links got almost same clicks (81 and 83, at the time of writing this post) the only difference is that both are submitted by different user. They are nicely moving up along on the front page of the (tech section).


How this happen and why Digg algorithm didn’t noticed? What about the people who clicked those links? Didn’t any of them noticed duplicate content and make the links appeared in the most Digged section? Or did they done it explicitly or what?