Because it is also your family's DNA. It is an action that affects not only yourself. You are infringing on the rights of all your relatives to NOT be included

Because it is also your family's DNA. It is an action that affects not only yourself. You are infringing on the rights of all your relatives to NOT be included in a public database when you do this. Honestly, you _should_ need my permission to post a photo of me on Facebook. You are selling my face to an exploitative company in exchange for access to their platform. You are giving Facebook worldwide non-exclusive license to do anything they want with my face, from using it in advertisements to using it to train facial recognition algorithms, all without my consent. It is pretty terrible how ignorant most people are of the potential harm they do to others this way.