If you are using Sitecore 9.x then you need to follow below steps to make it working -
Update IndexAnonymousContactData setting to true by default this is false in XConnect website.
You can find this setting into below xml files in Xconnect site-
I think just making these changes you would be able to see unknown user data in Experience profile.
And if you are using Sitecore 8.2 then below is the configuration.
<setting name="ContentSearch.Analytics.IndexAnonymousContacts" value="false"/>