You're right, locating friends is not currently supported. I would assume that this feature is implemented by simply sharing your device's (already recorded) latest location ping with your friends, in which case this is also currently out of scope for the project - the library only intends to interact with the "other-devices-find-my-device" network in order to be account-agnostic.
On a separate thought, if Apple has not taken concerns such as the one you portrayed into account when designing Find My Friends then I would suggest not using the system altogether. At that point it's only a matter of time before someone figures out how to extract the data. But that's an entirely different story and a personal consideration you'll have to make.