Are you avoiding patching your Magento site? If you're not sure take a look at the Magento site security patches page and make sure that you are aware of and on top of your Magento Security - and if you need help, give us a call.
Magento currently controls of the market share for ecommerce platforms. With the release of Magento this percentage is expected to increase. Magento is not just a new update, it is a new system on many levels.