Accept Reality
When it comes down to push or shove, there is no such thing as privacy on the internet. Any piece of mail you send, instant message you transmit... it's all in the public domain. It's not conspiracy theory, it is simple technological fact. What people do is up for conjecture, what they *can* do is not. Avoiding use of personal information on the internet is not even good enough; the companies you do business with store your information on their computers, like your credit card companies or marketing agencies. Accept Reality. We are entering the information age, and safeguarding some aspects of your privacy is an exercise in futility. We need to learn how to live with this, not pretend that it doesn't exist.

Don't want it read? Encrypt it!
Just because I support our government's war on terror doesn't mean that I want to give up my rights, my 'essential Liberty' as Ben Franklin so eloquently phrased it above. If the FBI shows up on my doorstep with a warrant, I'll gladly decrypt my recipe for Key Lime Pie, or let them read my love notes to Wendy. Until that day, I would prefer that the things I wish to keep private remain so.

Encryption software, such as PGP Desktop, is fairly inexpensive and ensures that your private documents remain private. Need to share business documents from the office? Don't trust your latest client leads or marketing efforts to e-mail? Set up an FTP server and use SSL to encrypt the traffic. Need secure Instant Messaging? Same thing. Get off of the public yappy chat products and install a business IM client that supports SSL.

We used to say "someone used my credit card", but now that nearly everything can be done online and merchants typically don't make you jump through hoops to prove that you are who you say you are, we call it "identity theft".

The Better Business Bureau has a good primer on Identity Theft for both consumers and businesses. Give it a read, you may discover that your habits leave you vulnerable to some of the nightmares other people are experiencing, like banks repossessing cars you didn't know you owned or police calling you about crimes you didn't commit.

Phishing for Idiots
Don't be an idiot. Use your head. Your bank is not going to send you an e-mail asking you for your password. Don't trust any "login" you receive in your mail. So what if it looks good, my 12 year old kid could probably use Bank of America's website to assmeble something that looks authentic. You would be suprised how many people are tricked into giving up their personal information from fraudulent "phishers".