With the growing smartphone penetration rate, smartphone settings remain one of the main models for information privacy and security controls. Yet, their usability is largely understudied, especially with respect to the usability impact on underrepresented socio-economic and low-tech groups. In an online survey with 178 users, we find that many people are not aware of smartphone privacy and security settings, their defaults, and have not configured them in the past, but are willing to do it in the future. Some participants perceive low self-efficacy and expect difficulties and usability issues with configuring those settings. Finally, we find that certain socio-demographic groups are more vulnerable to risks and feel less prepared to use smartphone settings to protect their online privacy and security.