I can't speak for other readers of HN, but I often ask those questions after seeing that Google points to unreliable sources without scientific editing. I'd expect someone who RELIES on a fact being true knowing how to check that fact with more than just Google.
As a rule, when I see you do that though you qualify your request to that extent.
Most of the 'citation needed' comments say just that and no more.
In the end though, the example linked is a pretty good one in that the base claim ('old spice causes infertility') is indeed somewhat supported but not to the extent that you're in acute danger: http://www.cosmeticsdatabase.com/browse.php?brand_id=705
I couldn't care less because I can't use aftershave anyway but I can see how that might be a problem if you used it every day (or even twice a day for the 5 O'clock shadow).
