My better half just picked up an iBook left for repair at the AppleCare desk in Paris. The box came back with an unexpected smoking surprise, right there in the Internet Explorer history. I saved a screenshot for your pleasure (and my records).
As you can see for yourself (and no, I am not going to link to that site, check it for yourself), repair technicians have broader interests than IT matters. Unless all recipes for planting, growing, harvesting and smoking pot is part of Apple's knowledge base.
The iBook had just one problem, a broken latch preventing it to remain firmly closed. Since it was not covered by an AppleCare contract (18 months old), the repair was billed 454 euros. I guess that leaves a comfortable amount of free time to get high at the expense of your customers.
Before you ask, I am not making this up. And to the repair person: you should consider Safari, it has a very convenient "Clear History" one click away from the application menu.