Speaking of that, I've come across 1.1.1.1 in several
places in NZ, most recently as the default router on the
wireless network in Rotorua public library.
Is it time for a little campaign to get rid of this heresy?
Probably not, presuming it's a /24 or similar network.
APNIC has already blacklisted 1.1.1.0/24 (and a few other networks from the 1/8 network), so whilst using it as basically private address space definitely isn't recommended, it shouldn't cause any issues going forward.
If they are using 1.0.0.0/8 or something more than just a /24 then it's definitely worthy of some action.