Painting and hiding rocks for strangers to chance upon is an international trend that started two years ago with a woman in Massachusetts. People paint the stones with colorful images or inspiring messages, then hide them at parks or outside stores — just about anywhere strangers are likely to find them. But the craze isn't catching on with American parks officials. The Nebraska Game and Parks Commission for example has asked visitors to refrain from hiding painted rocks in state parks and recreation areas, saying it violates a regulation against disturbing the natural landscape. For many visitors, encountering painted rocks "diminishes the land's beauty and the experience of being in nature," state parks administrator Jim Swenson said in a news release. Other state and national parks across the country have also asked guests not to hide painted rocks.