If you have a PayPal account or are thinking 
about setting one up, create or open an entirely 
separate checking account (not attached to your 
regular accounts) and link your PayPal to that.  
The same goes for any type of online payment or 
billing service.  I wouldn't even touch online 
banking (if you have it set up, maybe it's time 
to think about cancelling and closing that 
account in favor of opening a new one); NO 
network is secure (why? even internal employees 
with access can sell your information).

Also, rely on credit card purchases more often 
than not, since credit card companies are 
obligated to protect you from fraudulent 
purchases.  They may have a more expedient method 
of restoring your money.

In short, designate a specific bank account 
and/or credit card for ALL your online 
transactions.  As for that one bank account, keep 
your balance as minimal as possible and add funds 
only when necessary to make payments.  This will 
help you keep better tabs of your online 
transactions and reduce the risk to your overall 
money.

Unfortunately, this will not fully protect you.

ID theft can occur to anyone (hard-earned cash of 
many poor people still = lots of money for 
thieves).  A friend lost his entire savings 
($20,000) due to identity theft to a thief based 
in Washington DC, even though he lives in 
California.