When I worked at The Major US Motorcycle Manufacturer the salaried employees were warned during our orientation to never leave our workstations unlocked when we stepped away. Seems that in addition to the need for security, the "non salaried employees" were known to wander the non-production areas during their breaks looking for unattended PCs. The story told was that they would send e-mails, surf the 'net, and other things they shouldn't be doing. One fellow was caught after sending a rather unflattering e-mail to the plant manager when a security camera just happened to be pointing in the right direction. I learned rather quickly that Windows-L was so easy to do that it became a habit that I still do to this day.

Buying doughnuts for the team is good lesson and cheaper than losing your job over a security breach.