If you have the debugger with field content change-access, it is possible and quite easy to:
1. Break/change other user passwords in development or in production.
2. Change all ABAP program types including standard SAP program/screen without object key or developer key.
3. Change any database content directly. This is quite common to many developer's knowledge.
4. That a new SAP installation is possible to run forever with ALL authorization without installing a license key.
No demonstration will be shown here, but you are strongly advised to BE VERY CAREFUL about giving debugger access to users/developers.