Users flagged it. We can only guess why users flag things, but I suppose the sensationalism of the material, the high charge in the title, and the poor quality of the thread were factors. The thread also set off the HN flamewar detector.

I've turned off the flags for now and replaced the title with a less sensational subheading in the hope that that might support more substantive discussion, though it probably won't. (Edit: well maybe it is.)