Internet privacy

Many companies exist with a goal to obtain as much information about customers as possible, through loyalty cards and other kinds of customer schemes. This data is immensely valued by other companies, which may pay large amounts of money for access to this information for marketing purposes (often telemarketing). A huge public backlash against telemarketers led to the introduction of the National Do Not Call Registry in the United States, and similar systems in other countries.

With the increasing amount of e-mail spam being sent, often advertising products for sale, solutions to prevent the loss of privacy (as the spammers use social engineering and other similar practices to keep an up-to-date list of email addresses) have been developed. See e-mail spam for more information.

Laws regulating the use of personal information by companies have diverged significantly between Europe and the United States, with strong regulation in the European Union and requirements for explicit permission before personal information can be reused. Conversely, this area is largely unregulated in the USA. In the USA, the free speech provision of the First Amendment provides many protections against regulating the sharing and use of personal information.

http://en.wikipedia.org/wiki/Privacy