Considering our relatively small user base, its just not worth it for people to write for Mac. Then, considering how much easier it is to get into a PC 🙂 and the relative security of OS X, I wouldn't worry about it too much. Common sense should be about as much as you need to prevent anything from happening. And definitely, do not install Norton on your system. It might work on Windows, but it has been known to cause problems on numerous occasions on Mac.