Unfortunately, I know this wasn't the case - I didn't provide the link to anyone in our office, which has it's own IP, and I know they weren't aware of the HN p

Unfortunately, I know this wasn't the case - I didn't provide the link to anyone in our office, which has it's own IP, and I know they weren't aware of the HN post until afterwards. I also wouldn't publicly use this as an example if I knew I had been rigging the votes! So maybe it was just a case of HNers flagging the story as it became popular, as the title was fairly link-baity? I was under the impression that flagging a story kills it rather than suppresses it, but regardless, if that's the case then it makes sense. Edit: One comment in your example link by ColinWright seems to state 2 or more "flags" can cause this behaviour: http://news.ycombinator.com/item?id=3893207 http://news.ycombinator.com/item?id=3893207 If that's the case, it's probably best people don't know about it, as used maliciously it would be fairly disruptive.