Banks have implemented modern security measures, like motion-sensing and high resolution color security cameras, time-locked heavy vault doors, silent alarms, exploding dye packs, bait money and locator devices. Some banks supplement this protection with armed or unarmed security guards.
Gone are the days when expert safe crackers could crack the code to a vault or safe. Today's biometric technology makes non-violent methods of gaining access nearly impossible. Modern vaults and safes are also reinforced to the point that the amount of explosives needed to blow them open would likely create unwanted attention and run the risk of harming the building to the point of collapse. Even the most impregnable vault or safe needs to be able to be opened by someone. To circumvent vault and safe security features, robbers often kidnap the bank manager, but that is not always a successful workaround as banks have often removed the manager's ability to open the vault.
