Your comments

Ok I understand, thanks for the answer.

Did the person with the agent access right can enable something in order to allow other people to do the search without giving all the access rights ? When you are working with a large team it's pretty useful to search by name, not just for the moderator of the UserEcho. 
Right now you need to find one UserEcho of the person and click on his name in order to be able to see all the UserEcho that person created.