Default ID/PW For Apple Networks?

I'm seeing a lot of hotspots where the WAP's name is "Public"
with no security indicated.

But when I try to connect, I get an Apple login page that wants a
UserID/PW.

Anybody know if there's a default out-of-the-box ID/PW? I'm
thinking that at least some of these networks were set up by
somebody that just clicked the "Ok" buttons in some setup
procedure and didn't really care to implement any security -
analogous to all those "linksys" spots out there....
--
PeteCresswell