Hacker News Reader

Upvoted you, I asked myself the same question. Looks like a bot that annoys bloggers by notifying them that their writing is trending on various aggregators.

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The "pingbacks" are common on WordPress blog using WordPress comments. As you mentioned they simply appear when another website provides a backlink.

This is default behavior, but most disable it.

These comments link back to blogs that have links to "top stories on HN", linking directly to the stories.

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