  When technology enters applications and processes with a long tradition of
controversial societal debate, multi-faceted new ethical and legal questions
arise. This paper focusses on the process of whistleblowing, an activity with
large impacts on democracy and business. Computer science can, for the first
time in history, provide for truly anonymous communication. We investigate this
in relation to the values and rights of accountability, fairness and data
protection, focusing on opportunities and limitations of the anonymity that can
be provided computationally; possible consequences of outsourcing
whistleblowing support; and challenges for the interpretation and use of some
relevant laws. We conclude that to address these questions, whistleblowing and
anonymous whistleblowing must rest on three pillars, forming a 'triangle of
whistleblowing protection and incentivisation' that combines anonymity in a
formal and technical sense; whistleblower protection through laws; and other
norms and practices including organisational error culture.
