You have just enabled Portal User Visibility in Setup > Sharing Settings.

Community Managers are able to view all Community Users regardless of the organisation-wide defaults

Limited information on Community user profiles are publicly accessible e.g. Name, Photo, Reputation Level, Description

Limited information on Community user profiles are publicly accessible e.g. Name, Photo, Reputation Level, Description

All users with Write access to Cases on their profile are able to see all Cases owned by Community Members

Community users in the same community can see each other, regardless of the organisation-wide defaults

Portal users in the same customer or partner portal account can see each other, regardless of the organization-widedefaults