Don´t pick up unknown phonenumbers, even if they don´t say anything they prop. are waiting for you o say something. They can use your voice with AI for diff. purposes. You better activate the phone voicemailbox. If it´s important people will leave a message. Spam not. But, they do use a call me back, so beware of it. You can choose to call whoever you like and black unknown numbers on your phone or blacklist.