† The Sarbanes-Oxley Act requires publicly-held US companies and their EU-based affiliates, as well as non-US companies listed on a US stock exchange, to establish a procedure for the receipt, retention, and treatment of complaints regarding accounting, internal accounting controls, and similar matters (so-called ‘whistleblowing systems’). † The Austrian data protection authority has already issued four decisions on the compatibility of such whistleblowing systems with data protection law, which impose a number of detailed requirements that go beyond those contained in the Article 29 Working Party opinion. † Besides data protection issues, the implementation of whistleblowing systems also has important implications under Austrian labour and employment law.