Apple makes some pretty cool things but when it comes down to it I chose not to buy a Mac or I phone. As much I love the I Phones features, Apple makes me say no. I do not like being told that no system is safe from viruses, hackers, or ad ware. Why? Because it is not.
You see you may have read an earlier post on here on how to keep your browsing safer. Not safe but safer. There is no browser that is safe from any of these issues. I love Firefox but it is not 100% safe. Nor is the mac's browser, IE, Opera, or any other browser you use.
Hackers are just less likely to focus their time on any of those besides IE. Microsoft is the most popular making up around 3/4 of all users machines. Therefore your hackers are more focused on IE. Finding ways to penetrate it and get into your system.
The other browsers like the Mac browser makes up around 4% of browsers people use. This makes them a low target for hackers to intrude. Same thing with viruses and ad ware. Mac was was hacked and crashed on some peoples systems just hours after their release of their latest OS. Some one just trying to prove that mac was not immune to much of anything at all. Hackers just don't focus that much on creating resources to get into them. Point blank they just don't care. The more people use a browser or OS the more likely hackers will focus on it.
To be safer from hackers switch to less used browsers. I chose Firefox but hey what ever you like use. Apple makes for cool gadgets and pretty machines. However if you ever want to tweak you system I hope you don't have a mac. You won't be tweaking anything. Third party applications? Forget about it. Hardware switches? If your lucky. They are non configurable. You get what you get when you buy a mac. Nothing more but nothing less(as they have good hardware).I won't buy a mac because they make false claims like they are safe from viruses.
If you want to be the safest you can then you probably will need to switch alot. Like going to Linux all the way and never looking back. That is a tough transition and it is one that will take you some time to work like you want it to work if you are not a programmer.
Also don't leave your personal information on your system if at all possible. Jump drives, external hard drives, Back up Cd's, and even the dying floppy disk are your best friend. Use strong pass words. Your name, address, birth day, and even full words are not good. If your name is James try using "J@m3$" That is not a full proof one but it is probably around 85% stronger. Use at least 8 keys and make them caps sensitive ( j-@-M-3-$). Now that will help you more than you will ever know.