In all previous releases of Oracle, it didn't matter who you connected as, even as SYS - you could not grant privileges on someone else's objects.
SQL> conn / as sysdba Connected. SQL> grant select on SCOTT.EMP to PUBLIC; ERROR at line 1: ORA-01031: insufficient privileges
Normally we had to do some ugly workarounds (such as creating a procedure in the owner's schema, or hacking the passwords). But this has been resolved in 9i
SQL> conn / as sysdba Connected. SQL> grant select on SCOTT.EMP to PUBLIC; Grant succeeded.
This come courtesy of the new 'GRANT ANY OBJECT PRIVILEGE' privilege