Otherwise it would be a waste of time and money.
It would only make no difference if the result of the trial would be independent of the additional evidence that a surveillance state could in principle collect. But this would mean that the surveillance state is not necessary.
(a) Someone who has committed a crime
(b) Someone who was convicted of a crime he may or may not have committed
I was using (a). If you are using (b) then I understand where you're coming from. But I think it's not a good idea to use (b) because that would make everyone who is the victim of a miscarriage of justice a criminal when in fact they are not.
I watched an excellent speech of a law professor giving examples of people who broke the law without realising. Unfortunately, I don't remember how to find that video.
My point is that law makers define what a crime is. The effectiveness of law enforcement doesn't change that fact. It's not good to have laws on the statute book that wouldn't be there if only they could be enforced.
So if the surveillance state highlights the fact that we're all criminals, what that should tell us is that criminal law is in urgent need of a root and branch review.
The surveillance state is a very bad idea for many reasons. But saying that we reject the surveillance state because then laws could actually be enforced is a questionable argument. There are many better ones.
Odds are, in a few hundred years, we'll end up right back where we started.
But in my view, the much more important problem is that the surveillance state makes people afraid of getting wrongly accused of a crime. They stop doing perfectly legal things because they might be difficult to explain. I have observed that in my own behavior and I know others who have become very defensive in their use of the internet.
" We keep on getting stuck in investigations because of SIM cards not associated to a name!"
" Well let's ban anonymous SIM cards. People should be alright handing over their name for a cell phone."
"Alrighty then, sounds good"
Things like this happen because nobody in the room mentions the drawbacks. This can mainly be a question of social status ("Why would people be afraid of the police? They help you!").
Also, some people's value systems are different...
Most criminals aren't masterminds (and the few who are, are genrelly designed with other names, such as "politicians"); if you make it difficult to procure a phone, and a weapon, and to hide on the net, etc., many of them won't be able to assemble everything they need to commit serious crimes without getting caught.
One of the reasons why gun homicides are so much less prevalent in Europe is that if a minority of hardcore, resourceful criminals can find guns through black markets, most of the random losers can't: too complicated, too expansive, some planning-ahead required... And the many losers are the ones causing the bulk of criminality, not the few hardcore criminals.
Guns are not a fundamental piece or even really necessary, when living in a modern society. A SIM card on the other hand, is pretty darn convenient for the general population.
Whether they're right to belive they don't need one, that's an interesting but different question!
This is the same circular non-logic that permits officers to arrest you merely for resisting arrest.
The state decides to make wearing blue illegal; I continue to because I am a strong "blue believer"; thus, merely by insisting on wearing blue, I MUST hang with other law-non-abiders (aka "criminals") and thus become a "person of interest" to law enforcement for no other reason than sticking to principles.
Possessing an anonymous SIM card is no sole indicator that you are up to no good. Assuming so is problematic due to a good privacy argument by Martin Fowler: http://martinfowler.com/articles/bothersome-privacy.html
However, this was neither the OP's point, nor what I was answering too. He described the measure as ineffective, because most criminals would be able and willing to acquire an illegal SIM before using a phone. I believe this to be false and I explained why. Being dangerous for liberties is not the same as being effective from police forces' PoV; actually, these two qualities are negatively correlated most of the time.
Want to buy AK-47 with ammo in Paris? Just go to shady suburbs, if you know where to go/right people it's piece of cake for few hundred euros (not living there myself, but I have a colleague who comes from there and this is his consistent description).
Most likely, non-exclusive explanations:
* you underestimate the difficulty of acquiring such a weapon without being caught nor robbed;
* you overestimate the abilities of most criminals.
Incidentally, I happen to have spent about half of my life in Paris and its suburbs. I believe it gives me at least as much legitimacy as having watched a couple of sensationalist reports on French TV stations. Which, moreover, I have also watched :-)
Do you think someone who bought a sim-card from someone else is going to "register" that card with authorities? "Hey, I just bought this card, so you can't follow me. Where do I update my info?"
Once you know a SIM card is suspect, because it's been registered by a known addict and trafficker, you can put a wire on it even if you don't know who holds the phone. With this plus BTS-based geolocation, your chances of catching typical, opsec-illiterate criminals are vastly improved.
It's strange to think that other countries have restrictions on buying SIM cards, I can literally go to the corner store and get one for $20, with $20 credit on it.