Yes but I can take my laptop to my friend's place and use their internet, seemingly as someone who lives in that house. I think OP is talking more so about an I

Yes but I can take my laptop to my friend's place and use their internet, seemingly as someone who lives in that house. I think OP is talking more so about an ID (like driver's license type of thing) to use the internet. So that one might be able to say person X visited site Y (again, we have something similar to that now, but not exactly)