Community admins are able to track all their members activities. To access your users' information, click on your profile picture, go to Admin Panel, click on the Detailed Reports from toolbar on the left, and click on User on the very top of the window. You can see all the information and activities by your users.
As shown in the picture below, you will see a list of all your community member, their contact, and the number of Question, Answer, Comments, and Words posted by each of them. By clicking on Creation, you can arrange the list of your users from the newest to the oldest. Also, the Last Seen button shows the last time that a user logged into your community. You can also Export Users information at anytime using the button on the top right corner. It worths mentioning that in Tribe, you (as the owner of your portal) own all the user information and content created on your community.