Originally Posted by
pwnjitsu
You can still be hacked if someone wants your specific account badly enough. The gold farming hackers in general however wont bother. Its a deterrent, personally i got hacked about 3 times before i got one (twice before they were introduced) i didnt get hacked again until i broke my iphone and have the authenticator removed from my account. i was hacked again within 2 days of removing it and never again since putting it back on.
consider that without an authenticator on your account when everyone else is using them, your account is more appealing to hackers. Considering its not costing you anything to use other then having to enter a code when you change IP address its best to keep it on there.