Australian Privacy Commissioner: Metadata can constitute personal information

An interesting case from "Down-under" ...
Ben Grubb and Telstra Corporation Limited [2015] AICmr 35 (1 May 2015)
[...] 102. I am consequently of the view that the metadata Telstra holds in connection with an individual which permits that individual’s identity to reasonably be ascertained from that metadata constitutes the personal information of that individual under the Privacy Act.
103. I therefore find that in the present set of circumstances, the metadata held by Telstra to which it refuses to give the complainant access (the so named ‘network data’) constitutes the complainant’s personal information under the Privacy Act. [...]