Cellphones and Security
Brit security often combines maximum inconvenience for consumers with zero added safety. X-raying babies' shoes at airports is an example - and here's another on their tracking of cellphones.
We live in three separate countries, so use SIM-free cellphones, plugging in local SIMs when we get off the plane - that saves paying over $2/minute for local calls.
Cellphones broadcast for each call a) the phone's unique ID, and b) the SIM card's unique ID. So if you have a database of phone and SIM IDs linked to the names and addresses of their owners, you track who makes calls to who, and when.
I just tried to replace my phone in the UK, and found all Brit online stores won't deliver unless you provide some mix of name, address, age, DoB and occupation. The one I chose then accessed the (I thought private) Brit Electoral Register to check if I'm registered to vote at my address & finding I wasn't demanded an identity thief's cocktail of utility bills, passports and driving licenses "to confirm my identity". This is vastly more intrusive than the credit checking imposed by the folks who sold me my ThinkPad - which costs 10 times the phone.
The SIM purchase process also requires an address - but that's not verified, so you can invent one.
So it seems the Brits track cellphone calls.
That sounds like it would help catch terrorists looking to repeat the Madrid or London bombings. But it wouldn't - any sane terrorist will buy phones anonymously from a Pakistani market stall, and UK SIMs using false addresses.
So the net is an incremental cost for non-terrorists and no security gain.
And I'm buying my SIM-free cellphone in Italy.