Once when we came back from a trip (when our neighbor took care of our dog who was left at home), the dog met us at the door, all excited. We threw a ball, which she ran at top speed to catch, but then limped back. Threw it again, dog ran like crazy, limped back. After the third time this happened, while we were wondering if she could have hurt a paw or something, we walked in the house. Our sofa cushions were completely shredded.
We couldn't get that mad at her, of course. Obviously she'd been frustrated and lonely. The next day, when we went downstairs, we found she'd pooped on every other step. Our perfectly house-trained dog let us know exactly how she felt about having been left alone.