> Aside from using some user resource (like battery or network) how is this different from what website have been doing for a long time? 1) Network requests (a

> Aside from using some user resource (like battery or network) how is this different from what website have been doing for a long time? 1) Network requests (and thus communication with a remote machine that can log those requests) is an innate facet of the web. You can't load a site without explicitly choosing to make a network request. An app, however, might have no innate reason to make a network request at all. I think #1 is the most important, but also: 2) JavaScript can be disabled. 3) HTML/JavaScript and browser network requests can be reviewed. Mobile applications are almost completely opaque to users. 4) Cookies can be blocked to reduce tracking surface. 5) Web analytics and cross-web tracking is already something people are concerned about, resulting in the introduction of do-not-track and similar. Desktop apps have almost always explicitly asked permission before tracking users, whereas the web community seems to have brought to mobile a blasé approach to privacy and user respect.