Which goals and justifications are given for surveillance in public space?

Security and crime prevention, fighting terrorism, order and control in public space, efficiency and cost-effectiveness.

These are the "ends" in the question "Does the end justify the means?" (Der Zweck heiligt die Mittel?):

• security and crime prevention
• counter-terrorism
• order and control in public space
• efficiency
• cost-effectiveness

Each goal has to be weighed against the risks and side effects (privacy, misuse, doubtful effectiveness, cost), and against the conditions of the law (concrete threat, defined purpose, proportionality).