I got this error message this morning (see image) while trying to load a video from cnet.com. when I came back home from work this afternoon it still showed it and wouldn't let me connect online (even though I had full bars on my airport signal) It says something about a "blaster" type virus. What is that? Is that a PC thing or should I be worried too? I thought Macs don't get viruses. I checked off the box at the bottom and haven't seen the that warning message since. I'm able to use the internet not, but still...should I be concerned?