How should one view employee surveillance for assessing employee performance, which involves many aspects?

The issue is not so much about the circumstances under which surveillance may be taken, as about employer-employee relationship, which should be based on mutual trust. When monitoring employees, employers should follow the principles of legality, proportionality, and respecting the rights and interests of the data subject. Employers should inform employees of the purposes of personal data collection, and keep the surveillance to the possible minimum.