This is somewhat of a problem on mountain routes, where stack stones are sometimes used as navigational markers (cairns). The ethics of Leave No Trace say not to leave these cairns. Many times, people will put these up to aid others, but their route deviates from what could be a better/safe alternative. Or at least a different opinion on what one is. Then, you have two sets of cairns, each going off in its own way.

Until you get three sets.

This goes on, until no one can realistically understand what the cairns are trying to communicate.