The services of a social network focus on creating communities of people who have the same activities and interest, or for those who want to explore the activities and interest of others. Services such as instant messaging and e- mail are mostly web based to provide users ways to interact.

Attempts on standardisation of these services to prevent duplication of entries on interests and friends have led to privacy concerns. Concerns about giving out personal information and threats from sexual predators have been growing on big social networking services. Users must also be aware of viruses and data theft. On the other hand, large services usually work with law enforcement agencies to avoid such incidents. A perceived privacy threat also exists when someone posts a lot of personal information to government bodies and large corporations which allows a profile production on the behaviour of an individual.

There is also an issue on controlling data. This involves the information removed or altered by users which can be passed and/or retained to third parties. This danger became prominent when Quechup, a social networking site, gathered e-mail addresses from e-mail accounts of users for a spamming operation.

In scientific and medical research, asking information from subjects about their behaviours is usually scrutinised by an institutional review board. However, it’s not clear if same rules are applied to researchers that collect data from these social networking sites. These sites usually contain a great deal of data which cannot be obtained by traditional means. Although these data are public, republishing it for a research paper may be considered an invasion of privacy.