PostgreSQL
PostgreSQL Default Permissions
While I was trying to setup PostgREST (will make a post on that later), I noticed that there were a lot of issues with the default permissions for PostgreSQL Databases.
template1=# \dn+
                          List of schemas
  Name  |  Owner   |  Access privileges   |      Description       
--------+----------+----------------------+------------------------
 public | postgres | postgres=UC/postgres+| standard public schema
        |          | =UC/postgres         | 
(1 row)
The main thing that was worrying here was =UC/postgres. According to the docs,
this means that the postgres user is granting all other users in PostgreSQL USAGE and CREATE permissions on the database.