European Digital Rights (EDRi), an association based in Brussels, lists an unprecedented wide range of stakeholders, including child protection experts, survivors of CSA, police, national governments, UN officials, companies, NGOs and warning that the proposed measures are misguided and could do more harm than good.
https://en.wikipedia.org/wiki/Regulation_to_Prevent_and_Combat_Child_Sexual_Abuse
WP article on the proposed regulation.