As a system administrator it's my job to do what most people are too stupid to do on their own.  My biggest headache is email!  My mail server processed roughly 1.6 million email messages yesterday (1,602,547 to be precise).  That's alot of mail by any standards.  Of the 1.6 million roughly 30,000 and consequently rejected, another 16,000 were rejected because they scored a 10 or higher on the spam scale, but 500,000 were flagged as most likely spam because they scored between a [5 and 10), but allowed through because 10 of them might be important; most legitimate email scores a .5.  (the brackets above mean "[" <- including the number, and ")"<- upto, but not including). 

So what's the point?  The point is...people don't give their credit card out left and right, so why would they do it with their email address?  Take me for example...I personally receive just about no spam, at most 6 viruses.  Why am I so different?  Because I'm careful with my email address.  I don't give it out to every website that wants me to register, and if I do I read what I'm signing up for an make sure that emailing me is not part of the agreement.  I put a few special characters in my dummy accounts like an underscore (_) or a hyphen(-) which throws off spam generators. 

As for viruses I don't typically deal with people who are dumb enough to just open an attachment on their email and they are intelligent enough to keep their anti-virus software up to date in case they accidentally do.  Finally, I don't use the filesharing programs, which are the most popular way of getting spyware/viruses/SPAM to the end user!  Wake up people, you have a good thing with email, but if you continue to be so damn dumb then the government will start regulating it and you'll be sorry!