Please help me to understand this question.

I am having a hard time.

References: Employment Law

Scenario:

A bank in a small town is concerned with the perception of its employees by customers and others in the community. Branch managers are responsible for both the running of the branches and building community relationships. The bank decides that it needs to determine if certain personal habits are creating a negative perception towards customers. The bank decides to monitor its branch manager's off-duty activities in order to determine if this is creating concerns for the bank.

Question:

Should this bank, should any employer, have the authority to restrict what an employee can do off duty?If so, to what extent?And how would the employer enforce any such restriction?