<p>Sounds like what is done at som shopping Malls, I think maybe Bluewater was mentioned before. (I apologise for not digging out references, but I'm out about writing from my mobile phone.)</p>
<p>Basically the mobile network signalling within the shopping mall is monitored (using software defined radio hardware & open source software). When a phone registers with a network it gets a temporary device ids (a TIMSI if I remember correctly), and these are recorded so the the Mall owners can gather statistics on the routes people take through the mall, how long they spend in stores, at the food court, etc.. and see how in Mall events such as fashion shows, Santa's grotto etc affect behaviour. They should not at any point have any information that would identify actual people.</p>
<p>ttfn,<br>
Tony</p>
<div class="gmail_quote">On 22 Aug 2011 13:20, "John Wilson" <<a href="mailto:tugwilson@gmail.com">tugwilson@gmail.com</a>> wrote:<br type="attribution">> I noticed this sign on London today<br>> <a href="https://plus.google.com/108026745568270153735/posts/VF8hLKRkX4q">https://plus.google.com/108026745568270153735/posts/VF8hLKRkX4q</a><br>
> <br>> Any idea precisely what they are collecting?<br>> <br>> <br>> John Wilson<br>> <br></div>