Make a copy of the owner's diary and other sensitive documents, snoop through nightstand drawers... Equivalently, finding someone's personal computer unlocked and deciding it's all right to mirror the contents of its hard disk.
I think it's the equivalent of going down a public road and passing through a gate that was left open, onto private property.
While driving, off in the woods beside the road you notice a "no trespassing" sign, but it's not obvious that you're trespassing currently, even if you start to wonder.
A place on the disk was accessed that was unintended.
My point wasn't about the theft/piracy distinction. It was that your victim being incompetent at defending themselves is not a valid excuse for committing a crime against them.
Besides, counterfeiting one's furniture doesn't cause any embarrassment. I'd rather equate it to photocopying your secret business plan, or your collection of naked self-pictures.