I once cycled over to my brother's house and locked my bike up to his chain linked fence in the backyard. Near the end of the day, when I returned to my bike in order to leave, I observed that the lock was now neatly placed on top of my seat. The bicycle itself, was leaning against the fence. I immediately returned to the entrance of my brother's home in order to inform him of some type of property trespass, and possible bicycle mischief. He then fully disclosed to me, that he was the culprit, and that he used a bic pen to open my lock, just before I was to make my exit. He had been watching for my change in facial expression the whole entire time...