Have you checked that you are free of any malware and virii?
This could be using your bandwidth without you knowing.
When you say "I don't have any firewalls or anything" do you mean no antivirus or firewall software?
WPA2 hack: How secure is your Wi-Fi?
HP’s new Surface Pro rival is designed specifically for Adobe-using designers and artists
Best kids apps for iPhone & iPad
Que faire si son iPhone ou iPad est tombé dans de l'eau ?