Not a Sprint user myself, but that could just be what your local cell site is reporting for a name. It could be a site purchased by Sprint and never renamed, or it's named correctly and used under license by Sprint.
It's common to see when roaming outside of a home network.
Found it. Chameleon Provider is a system process used by Sprint. Goto Setting > Apps and click "Show System" from the options menu. Click Advanced from the app info page and it shows info about Sprint.
Not sure why it's showing this as the cell site name on the lock screen. I don't know this app's purpose.