A teenager in the UK saw a program about Google Earth, and decided to mark his (parent's) house. Now, it is unclear (at least from the linked article) if he wanted to really see if what Google Earth was displaying was real time or if it just seemed funny at the time.
A year later, a helicopter flying overhead noticed the image, and notified the family. The parents initially thought it was a joke, but asked their kids, and their son admitted that yes, he had drawn a large phallus on the roof. He has promised to paint over it when he gets back home.