How to search for a person?

Can a computer search tell how long a person was on a certain site?

• Answer:

  No. Although that information is often kept by sites, it is almost never made available to the public. So the search engines wouldn't see it. Perhaps you mean if the government confiscated a company server, could they easily find out how long a particular person was on? Not easily. Most web servers keep logs which can be scanned if they know some particulars about who they're looking for, such as their likely IP addresses. Login logs are easier and can be easily checked if their set up in an organized way. Assuming the user in question's login is enough to identify them.