I think the above comment refers to the proposal for SVG 1.2 (which never shipped) to include an API for opening raw network sockets: https://www.w3.org/TR/2004/WD-SVG12-20040510/#rawsocket

(It observes that this feature raises certain security risks, but promises to figure out by the next draft how to fix them. This of course never happened.)

I recall Hixie had a funny rant about this, but I can't find it.