CARS took on the difficult topic of the effectiveness of antitrust enforcement. At a seminar on March 30, 2022, speakers from the Netherlands, Lithuania, Poland and the UK discussed this issue. Important legal and organizational barriers were pointed out by Caroline Cauffman, Małgorzata Kozak, Marta Mackiewicz, Jurgita Malinauskaite, Sebastian Peyer, Aleksander Stawicki and Marcin Trepka. Jarosław Sroczyński discussed the passing-on allegation as a potential “circuit breaker” of infringers’ liability in chain-selling cases. Thanks to Dominik Wolski for the invitation and organization of the Seminar, Anna Laszczyk for moderating “my” session, and Maciej Bernatt for the keynote.