alt Hacker NewsI should not have paraphrased... it says "TERMS THAT PERMIT A RECIPIENT TO COPY, REDISTRIBUTE, AND MODIFY THE SOFTWARE WITHOUT RESTRICTION".
The way I interpret that is that redistributing cannot be restricted either, which wouldn't work for say, the GPL, as far as I understand it.
That indeed seems to rule out most open source licenses actually; one or another restriction, like including the license or not modify the license, will be in conflict. I’m pretty sure this sloppiness in phrasing is on purpose.