Some of responses in this comment thread look very much like blatant schoolyard bullying behaviour manifesting. "Why take things so seriously" "Spoilsport" et cetera ...
I was commenting more the reaction the HN crowd seems to present when someone dares to say this sounds like something they would be uncomfortable with, because that's very much the same one I remember from school. Of course in school you can't downvote, but the responses and dismissing attitude ("there's nothing wrong with the practice if you're not having fun with it") are eerily similar.
I mean technically this would be considered hazing. According to the "student handbook" of my alma mater hazing was defined as "making someone do something they do not want to do as requirement of membership" (paraphrasing here).
Personally, as a previous member of a greek organization, I find the definition ridiculous as it would qualify having prospective members study/be tested on the history of the organization as hazing.
Yeah, that definition is overly broad. Hazing requires harassment, embarrassment, or some other kind of abuse. Asking someone's underwear color is only harassment if they've got a history of inappropriate behavior, and embarrassment only if they've got serious socialization problems. Neither of which would reasonably be expected to be accounted for when asking the question in this situation.
18-22 year olds are all about hazing each other...
It's not like you have to be honest about what you're wearing, you could say any old thing - the email list police aren't spot-checking you to make sure you are indeed wearing yellow rubber ducky underpants.
I'm sort of surprised that there was not a sizable proportion of jokers that wrote-in "skidmarked"