Let me ask you something: would you trust a bank that locked its doors for the night but left all its cash in a big pile in the middle of the floor? Probably not—after all, if someone managed to get through the doors, nothing would stop them from helping themselves to the funds inside.
This is effectively how cybersecurity once worked, with the presumption that if someone had access to a network, they had permission to access any data on it. Fortunately, many businesses have made the switch to a better approach, known as zero-trust security.