The primary precaution is that employees should be warned that they should not plug unknown/untrusted firewire devices into computers containing sensitive information.
I'm suing you now. You didn't say anything about steak knives and I stuck one in a power outlet. My right arm is completely useless, and so are my right ear and nostril. I hope you're happy 😡
Nah, it's not really a problem at home. For companies and for any machines in public areas, it does pose some serious issues. FW and USB drives make it trivial to steal data that otherwise would be safely locked up on a server.