Any tool with as much power as databases can give must have some caveats, and databases certainly do. Databases are easy to build and maintain, and there is no way to keep unscrupulous people from using them as well as those that intend only good. Even when they are not deliberately used for foul purposes, databases can have unsuspected side effects.
Privacy is a major concern of the present and very near future. Although there have been databases since written language began, they were often very inefficient. There was usually little danger of the information in a database getting into the wrong hands, because computers tended to not be connected, and there was relatively little information being kept. Now the increased ease of database development along with increases in computer connectivity, processing and storage capacity have made the amount of information stored on databases increase exponentially. Now nearly every organization or corporation has some sort of database. When you give your name and address to a company by entering a contest or filling out a questionnaire, your information is almost certainly going to be entered on a database. That corporation is not always required to keep the information about you to themselves. Have you ever wondered why you get the combination of junk mail you do? Every one of those things in the mailbox has a mailing label on it generated by a database. You may have given them the address directly, or it may have been sold to the company by another company who you gave your information to.
Security of information is another concern. As more and more computers are linked via the Internet, there are more opportunities for data to be taken by those who should not have it. Be very careful using your credit card number on the Internet. Where will it go on the way to its destination? Will it be carefully guarded in the destination database, or can somebody just break in and assume your identity? Take the same care with other personal information. Who will get this information? Do you want them to have it? The legal system is wrestling with issues of privacy over the Internet. Technology is changing more quickly than the legal system can keep up.