Do you bank or invest or check your credit cards online? Do you ever shop online? If you're not careful, you could be sharing your logins, passwords and account access with the bad guys. Tech industry insider Marty Winston tells about one way that can happen.

I have a free piece of software for you, the e-mail says, just click here and download it. Don't go there. That's how the bad guys install keystroke loggers. Next time you check your bank or credit card balance online, they snag your login and password info. The only thing that turns out to be free is the headache.

Keystroke loggers are one form of spyware; like viruses, that's something you never want on your computer. Inexpensive software protection is widely available and dangerous to be without.