The sites set a temporary session cookie on a visitor's computer whenever a page is visited. Readers who do not intend to log in or edit may deny this cookie; it will be deleted at the end of the browser's session. More cookies may be set when one logs in to maintain logged-in status. If one saves a user name or password in one's browser, that information will be saved for up to 30 days, and this information will be resent to the server on every visit to the same Project. Contributors using a public machine who do not wish to show their username to future users of the machine should clear these cookies after use.
Edits or other contributions to a Page or its articles, user pages and talk pages are generally retained forever. Removing text from a project does not permanently delete it. Normally, anyone can look at a previous version of an article and see what was there. Even if an article is "deleted", a user entrusted with higher level of access may still see what was removed from public view.
User contributions are also aggregated and publicly available. User contributions are aggregated according to their registration and login status. Data on user contributions, such as the times at which users edited and the number of edits they have made, are publicly available via user contributions lists, and in aggregated forms published by other users.
We retain no details beyond your email address, username, password and full name if provided by you. No other information is requested, required, or stored. It is your responsibility to refrain from posting personal information about you or another person -- this is in clear breach of our terms of service