Here is a video about the Euclid software. This service makes the Wifi tracking even scarier because it can track across different stores, then they probably sell that data. <a href="http://www.youtube.com/watch?v=q4W1GIRHC_4" rel="nofollow">http://www.youtube.com/watch?v=q4W1GIRHC_4</a> <a href="http://www.youtube.com/watch?v=k86DxCqfHjY" rel="nofollow">http://www.youtube.com/watch?v=k86DxCqfHjY</a><p>Here is a way to opt-out of this particular service. <a href="https://signup.euclidelements.com/optout" rel="nofollow">https://signup.euclidelements.com/optout</a><p>It seems like it would be trivial to tie in the location tracking with the products someone purchases and if you are using a rewards card (like most grocery stores have) then the store has all of your information tied to your MAC address.<p>It's not just stores, any place could have these systems set up. Malls, airports, stadiums, schools, or even your workplace.<p>Is it possible to obscure or modify a phones wifi strength when not connected to a network to prevent this tracking?