It is quite difficult to prevent crime like the Melbourne ANZ card skimming attacks on the bank's ATM network. The weakest point of attack is usually people (i.e., users) and their habits.

The user of the ATM may not carefully check the slot where the card is inserted, the ATM may be located indoors, in a spot with poor lighting, or it may be used after hours when it's relatively dark. In all these cases it is possible not to notice the "fake slot" that the skimmers use.