Once upon a time, Mac users could brag they were much safer from malicious electronic attacks. After all, in the days before Google (GOOG), when Microsoft (MSFT) was the only uber-player in town, Windows was the perpetual malware target. Phishers, however, aren't discriminating; they're just looking for an account to plunge. So, both Apple (AAPL) and Microsoft users are threatened. Virus writers do tend to focus on the Windows operating system, which owns 90% of the OS market, but phishers are platform independent.
Phishing involves attempts to get a user to reveal information about their accounts. Once the soon-to-be victim clicks that link or fills out a form, the "transaction" is complete -- no operating system interaction necessary. As a result, there really isn't any advantage to using a Mac over a PC.

Who needs
When
Sometimes, the use of Google's many products have unintended and good side effects. Case in point: Google's search engine alone is being used to identify and track the activity of malicious websites. You know, the websites that attempt (and often succeed) in dropping viruses and 

