internet usage

[tobyw]

I got a huge bill from O2 for my internet account this month.
I have a sierra wireless connection. I got a bill for €180 compared with my usual €20 allowance for 15g.
I have not been doing anything different than other months where I keep within my allowance.
My main usage has been downloading guitar lessons from utube. They vary between 2 to 10 minutes in length.
A sign sometimes pops up advising me that there is high usage on google chrome.
One day alone cost €45 and I dont spend more than a few hours online.
Any ideas what could be wrong? I would appreciate any help.
Tobyw

[TTG]

Is your network protected? Someone could be connecting and using your bandwidth.

[tobyw]

I have AGV anti virus.
How can I check if someone else is using it.
Thanks TTG

[hc4361]

Is your router password protected?

[Whickerman]

YOu can always check your usage online using their website - posts usage up to the last connection.
You need only worry about someone else piggy-backing on your usage if you're using a wireless router. If you'r plugging straight into your computer then no problem.
But call O2. They can usually be a help.