Sometimes look-the-other-way loopholes stick around if they suit both sides. For example, brown-paper-bagging a bottle of beer with your buddies on the corner

Sometimes look-the-other-way loopholes stick around if they suit both sides. For example, brown-paper-bagging a bottle of beer with your buddies on the corner of your block, not causing trouble, then the cops have, though reasonable suspicion, the option not to enforce a law prohibiting drinking on your street corner (if you don't give them a reason to), an unwritten understanding that to my knowledge has been pervasive. If you don't believe me, watch HBO's The Wire, it's in there.