Labeling caches is important, but experience has shown here in the DC area that caches placed in high traffic areas are at-risk. Many new cachers are afraid that if a cache is not visible, a geocacher will not find it, so they leave it partially visible. After you find a few caches, you know where to look. Hiding caches very well, and avoiding popular spots will do a lot to keep caches from being plundered and/or being found by non-participants and mistaken for harmful objects.