not sure if this is the same thing, but i've seen something like this a few months ago. To connect to the interwebs, just select the "xfinitywifi" network to connect to, then sign in to xfinity account in the landing page! ..
..BUT
the connection sucked since the signal was from other units in my apt. building....
Here's my humble head-scratch: you pay for a comcast internet access, you might have bought or you're leasing the cable modem + wireless router, and perhaps there's an opportunity to opt-out (somewhere), but nonetheless my neighbor (who must at least have an xfinity account) is streaming their content through my connection. Somehow it seems like wireless usury.
you're right, i'm no longer mooching off of my neighbors now(maybe because the connection was so bad) but i feel like it's not unethical because comcast made it available, so why not use it?
..BUT
the connection sucked since the signal was from other units in my apt. building....