I've recently moved and had NBN installed with iinet. For the first week, I didn't have the appropriate modem, so I was connected via a cable.
I received an email last night from iinet saying I had already churned through 16 of my 20G allowance.
We do not download or stream any entertainment, including music.
I checked my internet usage and on one period of less than 2 hours shows that I used 7 GB of data. All I did during that time was check qantas, virgin, iwantthatflight, cheapo air and some hotels. I also emailed a one page excel spreadsheet.
Since the wifi was not connected, I can't really consider that someone hacked that.
For the past 18 years, someone else has paid my internet so this business with usage is a bit vague for me. But, the couple of people that I have spoken with think that is really not possible wiithout downloads.
Does anyone have any idea how I can figure out where this usage came from?
UPDATE: I am not sure how it happened, but the 7GB of usage on the 9th has disappeared from my account. I still have 3GB and 5GB showing on my account on the 11th and 12th. All of my other days now range from 0.22GB to 0.67GB so it appears that there was either a malware in my laptop that my free subscription to AVG got rid of or iinet fixed a problem. Thanks everyone who helped.
Sounds like JV's usage from his OzBargain posts.