I still dont see how.
As a pulbic wi-fi, its unlikely that any IP address could access the router its using, so they cant change settings/view the IP addresses of all connected devices.
they may be able to view devices connected to the network, but as the BB doesn't allow this, I dont see how anybody else using that network can see the device to access it.
"That's it then. Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings... and call off Christmas."