Coupling more accurate local data with usercontext and other sources of information will enable developers to create new algorithms to bridge the digital and physical worlds.
Because the script is being run in the context of the trusted web site, it has access to cookies such as session tokens, as well as any other userinformation available within the security context of that web site.
For instance, it may be perfectly ok to correlate location and time-of-day information, but it will be deemed unacceptable if a third stream of usercontext data is introduced.