If your with Eircom, I hear you'll get a nasty mail through the door telling you stop pirating. I think NTL are ok.
As mentioned once you have decent anti virus/ anti malware i.e AVG, avast, Norton, McAfee you'll be fine (In most cases :)). Sure most of the computers on the internet are owned by hackers anyway.. sure what's one more haha :)
I can assure you of this. I do a bit of part time security testing for a few of the main browsers
http://www.computerworld.com/s/artic...ows_kernel_bug
Paid for my 180 :)

