Funny enough, an alleged Chesterton's fence is very likely to be one of these derelict electric fences. People who advocate the "Chesterton's fence" argument (which is similar to and equally misguided as the precautionary principle) are essentially saying "whoever built this fence either didn't understand why they built the fence, or didn't manage to explain their reasoning to other people affected by the fence, and…
Chesterton’s fence isn’t “respect it forever” or “spend infinite resources”. It’s “don’t tear it down until you understand why it’s there”. The whole point is to avoid breaking something whose purpose you haven’t yet understood, because the original builders might have had a good reason that isn’t obvious to you. Once you’ve understood it, you’re free to remove it if that reason no longer applies.
int some_old_unmaintained_code(void vector){
// the qyick bwown fox bumped over a lazy do
int i=i;
// DON'T EDIT ABOVE THIS LINE;¥n¥n;¥n;;;;
// DOING SO BREAKS CODE