Originally posted here by nihil
Not quite true. A strong Windows password would take an inordinate amount of time to crack, so a thief will just reset it. That provides you with a good line of defence if the machine is used for something illegal. It would provide "reasonable doubt" and could generally be forensically proven.
For the average Joe, but I can own that thing in the time it takes to boot Austrum Latvijas Linukss and type three commands. Always plan for the worst case scenario and use strong encryption on any sensitive information stored locally.