Encryption is extremely important. Much of the data that exists today is sensitive and should be protected. Such information includes social security numbers stored by the government, account numbers stored by banks and credit card companies, and email addresses and passwords stored by websites. Without encryption, it would be very easy for sensitive data to be stolen and used malevolently. Social security numbers are frequently used in identity theft. Credit card and bank account numbers can be used to steal money from unsuspecting victims. Email addresses are frequently collected by spammers, and passwords can be used to gain unlawful entry into a computer system or hijack a website or an account on a website.
However, since encryption does exist, sensitive information like social security numbers can be hidden from thieves by encrypting it. Even if the thieves obtain the encrypted data, they lack the key that was used to encrypt the data, so they cannot decrypt it into plaintext. All they possess is a meaningless jumble of letters that they cannot use.