Today there are privacy laws (see Chapter 5) in many countries that protect their citizens from
invasion of privacy. In addition, many companies and organizations publish their policies on
privacy, usually on their Web sites, so that those who provide data to the organization understand
how their data may be used. Some companies go so far as to permit their customers to opt in or
opt out of having their data used for purposes other than the original purpose. For example,
American Express periodically includes with its bills a mailer to offer their customers the
opportunity to designate whether they wish to receive additional, non-bill-related mailings from American Express or from third parties to whom American Express may provide the data. By
returning the mailer, an American Express cardholder can indicate that he or she wishes to
receive American Express mailings but no others, and so on