Advocate General Mazak delivered his Opinion to the European Court of Justice on 22 April 2010 (in Case C-280/08P) on the appeal by Deutsche Telekom. His Opinion endorsed the General Court’s conclusion that the European Commission had not erred in its finding that Deutsche Telekom had abused its dominant position in Germany on the market for fixed telecommunications services by imposing an unlawful market squeeze, thereby limiting the ability for competitors to provide retail services to customers.