You will need
  • Personal information about a person, computer, Internet.
Nowadays most of the information about the user can be found in social networks. It is hard to imagine a young man or woman has no account in one of these networks. Older people in this respect are not far behind from young people. If you know any details about the man, you can use the search on the site: <url>,, and others like them. Often enough to know the name of the person or the date of his birth in conjunction with the city of residence.
People often register on those websites, topics which are of interest to them. If you know what the user is interested in, try to find popular websites or forums that are leaders in this field. On such sites, users rarely use their real data. Therefore it is better to search on the nick and e-mail. The desired person can give a date of birth, avatar, motto and style of communication.
If you search on certain sites doesn't yield result, use search engines. Type in the query name or mail address of the person. Perhaps the search engine will show you his text messages or profiles on the sites.
Suppose you know the user's email. Often people have multiple email addresses on different mail services. They can be both identical and different by a few characters. For example, postal addresses and can belong to one person. So try to search the mail with a similar name. If the search is successful, the address can also be included in a search of registrations on the websites.
Maybe you found a website on which people can be registered. But you are not sure. In this situation, you can try to do a recovery password on the website. This can be done if you know the mail address of the user or his username. If after the inquiry it was reported that mail is delivered the message with a link to recover your account, then it is likely the person really registered on this website.
Having access to the user's computer, you can watch history in the browser, which he often uses when working on the Internet.