An Australian freeway has been shut down. 'Computer glitch' or chinese hack job?

The freeway operator Citylink has been very tightlipped all morning however there is a growing whisper within the security industry in Melbourne that there weak security might have been breached from China.

I can't seem to comment in this thread for some reason so I'll update here: A friend just told me that network engineers from Europe are en route to Melbourne to assist in regaining control and that ASIO (Australian inernal security agency) is also now involved.