(1) In this Part:
(a) modification of identifying information; or
(b) impairment of the reliability of identifying information; or
(c) impairment of the security of the storage of identifying information; or
(d) impairment of the operation of a system by which identifying information is stored;
by a person is unauthorised if the person is not entitled to cause that modification or impairment.
(2) Any such modification or impairment caused by the person is not unauthorised merely because he or she has an ulterior purpose for causing it.
(3) For the purposes of an offence under this Part, a person causes any such unauthorised modification or impairment if the person's conduct substantially contributes to it.
(4) For the purposes of subsection (1), if:
(a) a person causes any modification or impairment of a kind mentioned in that subsection; and
(b) the person does so under a warrant issued under the law of the Commonwealth, a State or a Territory;
the person is entitled to cause that modification or impairment.