The internet's security relies on an almost impenetrable wall built around it. The king appoints gatekeepers that are each entrusted with a gate they must protect. The gatekeepers must follow a rigorous interrogation process to verify the ID of anyone who wants to pass through their gate. Only then are they permitted to unlock it.
The king was very careful to ensure all the gatekeepers were following the process correctly. It did not occur to anybody that one of the gatekeepers could be using a dirty rag to jam their gate closed instead of a lock.
Once discovered, the wall could be trivially bypassed. The security of the whole internet was immediately broken. Rebuilding the wall to block up the dodgy gate took much effort from very many people.
The king was very careful to ensure all the gatekeepers were following the process correctly. It did not occur to anybody that one of the gatekeepers could be using a dirty rag to jam their gate closed instead of a lock.
Once discovered, the wall could be trivially bypassed. The security of the whole internet was immediately broken. Rebuilding the wall to block up the dodgy gate took much effort from very many people.