1. An electronic device comprising: a capacitive fingerprint sensor having a fingerprint sensing surface forming part of an exterior surface of said electronic device; a protective film arranged on at least a portion of said exterior surface of said electronic device comprising said fingerprint sensing surface, wherein said protective film is arranged to at least partially cover said fingerprint sensing surface; and wherein said protective film comprises an electrically conductive verification pattern covering at least a portion of said fingerprint sensing surface such that the fingerprint sensor can be controlled to capture an image corresponding to the electrically conductive verification pattern.