I am not sure this is a new threat, a user's list of known SSIDs has been a recognized threat to privacy for a long time. You do not even need to have an app installed on Alice's phone to track her location. All Eve has to do is listen for beacon probes from alice's laptop and Eve can get a good picture of where Alice has been and more: "Show me your SSIDS I'll tell you who you are"[1]
[1]: http://blog.rootshell.be/2012/01/12/show-me-your-ssids-ill-t...