I wouldn't exactly say there's a zero chance. There's an almost zero chance if post dates are close together but not if they're further apart. Cable connections work like, for example, AOL connected via a router. They're both permanently connected and so have an IP address for the whole of the time they're connected. But disconnect and reconnect and a different IP address is assigned which again remains the same for as long as the connection is maintained.
I am aware how cable works - check the site I'm an admin on It takes more than just a disconnect / reconnect - if you do that you will get the same IP reallocated to you (unless you change MAC address)