Definitely older than Hacker News. I got it from Reddit, and I think Reddit got it from UseNet (possibly via 4chan or IRC).
I paraphrased though, and the grandparent post must have a better memory (or better Google skills) than me, which is probably why you can't find an exact match...
The oldest versions I've heard went something like “Welcome to the internet, where the men are men, the women are men, and the children are FBI agents.”
Pretty sure the line goes back further than that though.
My guess is that it’s a parody of A Prairie Home Companion’s line about “Lake Wobegone, where all the women are strong, all the men are good looking, and all the children are above average.” Though that might itself be playing on some earlier such line?
I think of the hitch-hikers guide to the galaxy (from the 70s?): "Where men are real men, women are real women and small furry creatures from Alpha Centori are real small furry creatures from Alpha Centori."
Which is presumably itself a parody, I'd guess of some standard line from a Western. But I couldn't pin it down to exactly where.
That the internet has been thus for a long time is disappointing, but not surprising.
I've studied oral-formulaic poetry, and one of the interesting aspects of it is that everyone tells the same stories over and over, and what makes one retelling superior is not the actual content, but the way it's delivered. I may well have seen it before. But long line lengths and easy Verdana text make HN good for memorable one-liners, and your retelling had punctuation, capitalization, and pithiness.
http://news.ycombinator.com/item?id=1546789