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.”

Example from 2001: http://www.bash.org/?2832

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?

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.