Securing the data.

By default public has no rights at all.  In general it should stay
that way.  If there is a special situation that requires using the
public role, the use should be tightly controlled.  That means
granting the absolute minimum of rights.  I would not want ANY public
role to have INSERT, UPDATE or DELETE rights.  If a public user has to
update a database it should be through stored procedures, where the
EXECUTE right for only the stored procedures required would be
granted.

Roy Harvey
Beacon Falls, CT