Saturday, March 07, 2009

Saturday Morning Security and Such

Better late than never, right? It seems that some people are coming to the realization that all that's been going on for the last 6 years is actually not pointing in the right direction. Surprise!
The latest person to submit to reason:
Ex-spy chief Dame Stella Rimington says ministers have turned UK into police state - Times Online
Dame Stella Rimington, the former head of MI5, has accused the Government of exploiting people’s fear of terrorism to restrict civil rights.

Ministers risked handing a victory to terrorists who want people to “live in fear and under a police state”, said the former spy, who retired as Director General of the Security Service in 1996.

I'm glad you feel more at ease to say this sort of thing now that you're retired.
Brian Eno, yes that guy, is quoted later in the article:
Brian Eno, the musician turned activist who will speak at the Convention on Modern Liberty later this month, said that Dame Stella was right.: "When the government passed its 'anti-terror' laws, it reassured those who campaigned against them that they would only ever be used in the most extreme circumstances," said Eno.

"Within a couple of years they had been used to eject an 80-year-old heckler from a Labour Party Conference, to arrest a woman for reading out the names of British soldiers killed in Iraq, and to freeze the assets of Icelandic banks in England. This is the problem with vague legislation of this type: it invariably gets called into use whenever anybody does anything that the government finds embarrassing or the police find inconvenient."

As a related note criticizing the track we're on, Ben Goldacre has a really good post debunking datamining. It's largely tied into this article. The key point to the article follows:

Datamining for terrorists would be lovely if it worked - Bad Science
If you have 10 people, and you know that 1 is a suspect, and you assess them all with this test, then you will correctly get your one true positive and – on average – 1 false positive. If you have 100 people, and you know that 1 is a suspect, you will get your one true positive and, on average, 10 false positives. If you’re looking for one suspect among 1000 people, you will get your suspect, and 100 false positives. Once your false positives begin to dwarf your true positives, a positive result from the test becomes pretty unhelpful.

Remember this is a screening tool, for assessing dodgy behaviour, spotting dodgy patterns, in a general population. We are invited to accept that everybody’s data will be surveyed and processed, because MI5 have clever algorithms to identify people who were never previously suspected. There are 60 million people in the UK, with, let’s say, 10,000 true suspects. Using your unrealistically accurate imaginary screening test, you get 6 million false positives. At the same time, of your 10,000 true suspects, you miss 2,000.

Interesting. A couple of minutes on Google allows me to back of the envelope this this principle for Canada.
Population of Canada, 33 200 000 (Jul 2008 estimates)
CSIS estimates of the number of active terrorists in Canada: 350 members in 50 terrorist groups. (source)
First that's a 2000 estimate, so let's be generous and assume that George W. Bush's efforts to combat terrorism have been successful and the number is now 1000 members.
Let's also give the search algorithms unrealistically high efficiencies of a 95% success rate for identifying terrorists and an unrealistically low false positive rate of 5%.
That would mean:
950 of those active terrorists would be identified.
50 would be missed.
1 660 000 innocent Canadians would be incorrectly (and I presume to their inconvenience) identified as terrorists.
Good luck with that.
Now, if the number of terrorists were 1 000 000 in Canada, and we can all agree it's not that high, you would still have half again as many false positives as actual identified terrorists, and the number who slip through the net would be enough to populate two or three East Coast towns.
Now tell me that's worthwhile.

After note:
People are starting to fight back.

Liberty groups unite to defend UK rights | UK news | The Observer
The government and the courts are collaborating in slicing away freedoms and pushing Britain to the brink of becoming a "database" police state, a series of sold-out conferences in eight British cities heard yesterday.

In a day of speeches and discussions, academics, politicians, lawyers, writers, journalists and pop stars joined civil liberty campaigners yesterday to issue a call to arms for Britons to defend their democratic rights.

No comments: