Do you mean that I can't take some age-old idea, process or system, add "on the Internet" or "with a computer" to it and patent it?
Dog-walking on the Internet sounded so promising too.
I prefer a hostsfile myself.
Blocking at the router means that I don't have to tweak several hosts files, plus it covers my Android devices that don't have easily accessible hosts files, but do have pre-installed Facebook apps that call home every night with huge permissions that send who-knows-what, and can't be uninstalled. (When I finally rooted the tablet, I did some cleaning.)
Even the simplest home router can do that. They usually have a parental site blocking feature.
I think someone just wants to build the biggest botnet ever! (Kidding...)
Santa Claus can even be at two places at the same time!
That would violate clausality.