They feel (incorrectly) like they control their smartphones. As far as their fears about this being used for privacy violations and/or mass surveillance, they

They feel (incorrectly) like they control their smartphones. As far as their fears about this being used for privacy violations and/or mass surveillance, they are 100% justified. The Snowden leaks, as well as what we know from leaks about pretty much every major and a lot of minor tech companies, have shown that if it can be abused, it will be abused. By the state, tech companies, or both.