  We introduce the task of anonymous metrology, in which a physical parameter
of an object may be determined without revealing the object's location. Alice
and Bob share a correlated quantum state, with which one of them probes the
object. Upon receipt of the quantum state, Charlie is then able to estimate the
parameter without knowing who possesses the object. We show that quantum
correlations are resources for this task when Alice and Bob do not trust the
devices in their labs. The anonymous metrology protocol moreover distinguishes
different kinds of quantum correlations according to the level of desired
security: discord is needed when the source of states is trustworthy, otherwise
entanglement is necessary.
