5 ms·

So? 1/10,100 isn't bad at all. Suppose you have many independent tests, each creating watchlists. Suddenly you have the intersection of individuals hitting each

So? 1/10,100 isn't bad at all. Suppose you have many independent tests, each creating watchlists. Suddenly you have the intersection of individuals hitting each of these, and the number of "interesting" individuals narrows. This is not a univariate problem; they're likely correlating everything to everything, and have adaptive snooping methods based on how high you are ranked a risk. Once you're high enough, field offices know about you and will keep a closer eye. It's really not a needle in a haystack (and as a privacy nerd, it pains me to say this, but I bet it is working).

mtgx 13y ago
I think what his data shows is that out of 10,000 terrorists, it might help catch one. Remember they've been doing this for more than a decade, and it still didn't help them with the Boston bombers. They even had the guy in custody before. Still didn't help. The abuse of surveillance power is not effective, even if it was legal/constitutional.
- jlgreco 13y ago
  No, his calculation shows P(baddy|flag)=1/10,000. In other words, given that the system flags somebody, there is only a 1/10,000 chance that this person was correctly flagged. This is given the absurdly high P(flag|baddy) of .99 (a terrorist raises a flag 99% of the time... good luck with that.) and a P(flag|innocent person) of .01 (meaning that in the US an absolutely staggering 3.19 million people would be wrongfully flagged by this system). Then there is P(baddy)=1/1,000,000, which implies that we believe there are 300+ terrorists currently in the US that desperately need to be caught. What the hell have those 300+ terrorists been doing in the past few years? Wishing they could only find guns the the great US of A? 1/10,000,000 is a far more reasonable number, though even 1/100,000,000 is probably being generous. 1/10,000 is absolutely abysmal. When you start punching in more realistic numbers though the result becomes much worse and you rapidly approach a situation where you would have more luck flagging random US citizens as uncaught criminals than you will with using this system to identify terrorists. If you permit those sort of absurd odds, then even hiring "forensic psychics" to investigate murders in small towns starts to make sense... This sort of screening flat out does not work for something as rare as terrorists. It only works when you start bumping your P(baddy) way up (dropping P(flag|innocent person) is not practical, and raising P(flag|baddy) to even more absurdly high levels only gets you marginal improvements). Replace 'terrorist' with 'person of interest to the DEA' or 'tax cheat' and suddenly this sort of screening starts to look a hell of a lot more practical.... hmm....
- dwild 13y ago
  Wait, media were talking about Prism before? You have no idea the effect they had on terrorism. We can't tell with the information we have currently. We don't even know which information is true. Maybe they saved ton of terrorist attack, maybe they got multiple criminal or killers with that, but we won't know because they never said it was with the help of Prism. All we know is that this project cost 20 millions, they had access to informations from a dozen companies, which is easily multiples hundred terabytes, probably even petabytes. I doubt 20 millions is enough to do anything useful with these informations. However can we even trust theses slides?...
  - flyinRyan 13y ago
    Why on earth would you assume it's working? This is immoral and wrong, it's up to the government to show that it's buying us something (but I'd be against it even then). If they don't show that we should assume it hasn't stopped even one crime.
flyinRyan 13y ago
It's clearly not working. Nothing anyone is doing is working. Look at the cases where the US government actually "catches" a terrorist; they're all clear-cut entrapment cases. If these clowns are so effective, why would they hide the real successes and show us the clearly illegal ones?
- vsbuffalo 13y ago
  It's very simple: there would be mass panic if they showed how successful they've been. If they take down a terrorist plot every 8 months, this means that there'd be a continual cycle of racial profiling and panic if made public. Look how crazy and destructive the internet got after the Boston bombing. If the US government publicized successful terrorist takedowns, do you honestly think it would be any different? One can't observe (as a US citizen) a lack of successes and estimate whether the program is working or not, because that information would be intentionally hidden. It's an unknown as to whether (1) there are more plots than we know of and (2) the program is working in capturing and preventing these plots, and they remain hidden to us after.
  - flyinRyan 13y ago
    >It's very simple: there would be mass panic if they showed how successful they've been. We don't know that. But I suspect if they really were stopping lots of plots people might question why there are people so desperate to kill us. Nonsense like "hate us for our freedom" isn't going to hold up long if we are constantly getting attack. Having said that, I don't believe this is the case. Based on what the government has shown (entrapment cases) I'm sure they'd blast it out on every station if they managed to stop a real terrorist plot. >One can't observe (as a US citizen) a lack of successes and estimate whether the program is working or not, because that information would be intentionally hidden. And one can't observe if my anti-tiger rock is actually protecting me from being killed by tigers. But I'd still call you a moron if you paid billions for my rock and gave up a ton of your freedoms to have it.

mtgx 13y ago

I think what his data shows is that out of 10,000 terrorists, it might help catch one. Remember they've been doing this for more than a decade, and it still didn't help them with the Boston bombers. They even had the guy in custody before. Still didn't help. The abuse of surveillance power is not effective, even if it was legal/constitutional.

jlgreco 13y ago
No, his calculation shows P(baddy|flag)=1/10,000. In other words, given that the system flags somebody, there is only a 1/10,000 chance that this person was correctly flagged. This is given the absurdly high P(flag|baddy) of .99 (a terrorist raises a flag 99% of the time... good luck with that.) and a P(flag|innocent person) of .01 (meaning that in the US an absolutely staggering 3.19 million people would be wrongfully flagged by this system). Then there is P(baddy)=1/1,000,000, which implies that we believe there are 300+ terrorists currently in the US that desperately need to be caught. What the hell have those 300+ terrorists been doing in the past few years? Wishing they could only find guns the the great US of A? 1/10,000,000 is a far more reasonable number, though even 1/100,000,000 is probably being generous. 1/10,000 is absolutely abysmal. When you start punching in more realistic numbers though the result becomes much worse and you rapidly approach a situation where you would have more luck flagging random US citizens as uncaught criminals than you will with using this system to identify terrorists. If you permit those sort of absurd odds, then even hiring "forensic psychics" to investigate murders in small towns starts to make sense... This sort of screening flat out does not work for something as rare as terrorists. It only works when you start bumping your P(baddy) way up (dropping P(flag|innocent person) is not practical, and raising P(flag|baddy) to even more absurdly high levels only gets you marginal improvements). Replace 'terrorist' with 'person of interest to the DEA' or 'tax cheat' and suddenly this sort of screening starts to look a hell of a lot more practical.... hmm....
dwild 13y ago
Wait, media were talking about Prism before? You have no idea the effect they had on terrorism. We can't tell with the information we have currently. We don't even know which information is true. Maybe they saved ton of terrorist attack, maybe they got multiple criminal or killers with that, but we won't know because they never said it was with the help of Prism. All we know is that this project cost 20 millions, they had access to informations from a dozen companies, which is easily multiples hundred terabytes, probably even petabytes. I doubt 20 millions is enough to do anything useful with these informations. However can we even trust theses slides?...
- flyinRyan 13y ago
  Why on earth would you assume it's working? This is immoral and wrong, it's up to the government to show that it's buying us something (but I'd be against it even then). If they don't show that we should assume it hasn't stopped even one crime.

flyinRyan 13y ago

It's clearly not working. Nothing anyone is doing is working. Look at the cases where the US government actually "catches" a terrorist; they're all clear-cut entrapment cases. If these clowns are so effective, why would they hide the real successes and show us the clearly illegal ones?

vsbuffalo 13y ago
It's very simple: there would be mass panic if they showed how successful they've been. If they take down a terrorist plot every 8 months, this means that there'd be a continual cycle of racial profiling and panic if made public. Look how crazy and destructive the internet got after the Boston bombing. If the US government publicized successful terrorist takedowns, do you honestly think it would be any different? One can't observe (as a US citizen) a lack of successes and estimate whether the program is working or not, because that information would be intentionally hidden. It's an unknown as to whether (1) there are more plots than we know of and (2) the program is working in capturing and preventing these plots, and they remain hidden to us after.
- flyinRyan 13y ago
  >It's very simple: there would be mass panic if they showed how successful they've been. We don't know that. But I suspect if they really were stopping lots of plots people might question why there are people so desperate to kill us. Nonsense like "hate us for our freedom" isn't going to hold up long if we are constantly getting attack. Having said that, I don't believe this is the case. Based on what the government has shown (entrapment cases) I'm sure they'd blast it out on every station if they managed to stop a real terrorist plot. >One can't observe (as a US citizen) a lack of successes and estimate whether the program is working or not, because that information would be intentionally hidden. And one can't observe if my anti-tiger rock is actually protecting me from being killed by tigers. But I'd still call you a moron if you paid billions for my rock and gave up a ton of your freedoms to have it.