Since March 2024, the undertakings Alphabet/Google, Amazon, Apple, Byte-Dance/TikTok, Meta, and Microsoft must comply with the obligations of the Digital Markets Act (DMA). Within the first month after the 6-months implementation period has ended, the European Commission opened investigations against Alphabet/Google, Apple, and Meta for non-compliance with the obligations in the DMA. All proceedings can be traced back to related competition law cases. However, only two proceedings follow the same reasoning as their competition law role models, while the case against Meta reveals that the approaches under the DMA can and will deviate significantly to those under competition law and data protection law.