When you buy a "smart" camera, you are not buying a tool; you are buying a subscription to a surveillance network. Most consumer camera systems upload every motion event—every leaf rustle, every Amazon delivery, every child's tantrum—to cloud servers owned by companies like Amazon (Ring) or Google (Nest).
Many forget that security cameras also record audio. In many U.S. states, two-party consent laws require everyone being recorded to know they are being recorded. A hidden camera capturing a private conversation could be illegal. Hidden camera in the women-s toilet of McDonald-s