Wikipedia requires no personal information from anyone who wishes to edit it. The IP addresses of editors are logged, but only visible if the editor has not created an account name. Some editors use their real name for their account, most others use a pseudonym.

Wikipedia editors have a user page that they can use to talk about themselves, list their interests, their country of origin, or just a poem or picture they happen to like. Some user pages are nearly barren, others list a plethora of information about their subject.

There are some reasons why it might not be a good idea to list your last name, street address and/or phone number on your Wikipedia user page (or indeed, anywhere else on the internet). The main reason is that this information is freely accessible to just about everyone. If for instance you are involved in an edit dispute, a bad-tempered user could use your phone number to make an obscene phone call - or worse, report you for some imaginary offence to the police.

Though it hasn't happened on Wikipedia yet (as far as we know), some other websites have been in the news because a pedophile was using contact information available on those sites to make contact with young children. Even among adults, there have been reports of off-line harassment and sexual assault from people who found the victim's identifying information online.

Although it is your own responsibility, you are advised not to list personal details such as contact information on your user space, or to discuss them over the various contact channels, including IRC.

If you have in the past posted contact information anywhere and you wish it deleted, you can contact any administrator to delete the information, which will hide it from everybody except other admins. Alternatively, you can contact the people at Request for Oversight, who can hide it from everybody, including administrators (and themselves).

• Posting personal information about someone else (regardless of whether it's true or not) is a serious case of harassment and usually results in the offender getting permanently blocked. See Wikipedia:Harassment#Posting of personal information (also known as WP:OUTING.) and Wikipedia:Respect privacy
• Under certain circumstances, the posting of personal details (whether true or not) may be considered disruptive and result in sanctions. See WP:CHILD.