At the end of 1999, Pieper founded Insight Capital Partners Europe, a private investment fund for IT-businesses, later operating under the name of Favonius Ventures, particularly in the field of e-commerce. In November 2000 he became Chairman of the Board of Lernout & Hauspie, a Flemish company specializing in speech recognition technology. Pieper was instrumental in uncovering a financial scandal at this company, which took place in the period 1996–1999, before he joined the company. In cooperation with the Belgian authorities, Pieper helped to secure information that ultimately led to the formal charging of the founders Jo Lernout and Pol Hauspie. Pieper left as Chairman of the board after the shareholders decided to appoint a new CEO and board.