[shishir456]

Deduplication on the current stories was simple to implement as a first hack and that is why I did a prototype for it. But it is very easy to extend this idea to stories across time. All we need is to maintain an index of all hacker news stories and the same approach can very easily be implemented to prevent reposting old content too.

[brudgers]

Preventing the reposting of old content is undesirable. A story that was posted "2516 days ago" has zero value to the community today at most. If today it prevents a posting that provokes meaningful dialog the old story is likely detrimental. HN is a very different community than it was five years ago.