It's not verboten. But, candidly, it is kind of rude. What's the difference between someone at, say, the EFF "proving" something happened by running an experiment and writing about it publicly, and someone on Hacker News doing the same?
I disagree that it is rude to point out something is an anecdote.
The proof has to do with the technical details, not the authority figure posting it. If someone from the EFF wrote a blog post with the same content as these HN posters, I would be similarly dismissive of this as "proof."
