Help! We've got an iMac running 10.6.8, iPads, iPhones, a Macbook and a Windows laptop and have turned everything off and its the iMac with the issue. We've got 150GB data per month, which should be plenty, but we are using it in just a few days - and not even using the imac! It runs constantly, but just receiving std emails and for the occasional web search. Everything else is done by phone or ipad. I found a torrent app on here last month which I deleted, and the data dropped right back to normal, for a week. Then it jumped right up again. The firewall is switched on in system prefs, and I've also tried the "block all incoming connections" but watching the data usage on suplusmonitor, it is not decreasing at all! I've been through all other apps, and there is nothing but the basics, and searched online with no answers. Does anyone have any ideas what to do other than leaved it switched off!!?