Why can I not see any members in the search?
Check your search parameters, especially the advanced search if you're a premium user. Results are based on what search parameters you have set. Adjust these parameters to see more members.

How can I block/unblock or report another member?
To report or block/unblock someone, go to the person's profile and click the 'More Options" button.

How can I contact Admin?
At the bottom of the page is a Contact Us button, click that to send us a message. 

What does the option "Hide my presence" mean in the user profile settings?
If the user activates the option "Hide my presence" then other users will not be able to see that user on the site. The profile of this user will not be available in search and for visiting by other users.