Researchers Find Gaps In Iranian Filtering

I Don't Believe in Imaginary Property writes "With all the turmoil and internet censorship in Iran making it difficult to get an accurate picture of what's going, security researchers have found a way to locate gaps in Iran's filtering by analyzing traffic exiting Iran. The short version is that SSH, torrents and Flash are high priorities for blocking, while game protocols like WoW and Xbox traffic are being ignored, even though they also allow communication. Hopefully, this data will help people think of new ways to bypass filtering and speak freely, even though average Iranians have worse things to worry about than internet censorship, now that the reformists have been declared anti-Islamic by the Supreme Leader. Given the circumstances, that declaration has been called 'basically a death sentence' for those who continue protesting." Reader CaroKann sends in a related story at the Washington Post about an analysis of the vote totals in the Iranian election (similar to, but different from the one we discussed earlier) in which the authors say the election results have a one in two-hundred chance of being legitimate.

Comments

The 1 in 200 bit is garbage

[skelterjohn]

To help illustrate, I am going to flip a fair coin 100 times. Actually i'll have a computer do it for me. I end up with...

*drumroll*

48 heads and 52 tails!

Seems pretty reasonable. The question is, now, how likely is it that I flipped exactly 48 heads and 52 tails?

If you know something about a binomial random variable (which is what we just sampled from), you know that this is (100 choose 48)*.5^(100) = .0735!

Wow...and that was with only 100 random coin flips. A 1 in 20 chance that, by their metrics, this was a fair set of coin flips (see where the logical incongruity happens?)

The bottom line is the probabilities we get out of this are not useful to think of as absolute...with so many possibilities the likelihood that any one of them in particular pops up is extremely small. However, we know that at least one of them *will* pop up. It is more useful to think of these likelihoods as relative probabilities...if you take the ratio of any two of them, that does tell you how many times more likely one is to happen than the other.

Maybe a useful test would have been to randomly generate some results and look at the likelihood ratio?

Beyond that, to truly say something like "and the probability that they cheated was X", you need to have prior distributions over cheating and not cheating.

A good example for why this is true is the following classic example: you take a test for a disease that has a 99% chance of correctly diagnosing you, and one out of every 10000000 people have this disease. It diagnosis you as positive. Should you be worried?

The answer is: given only that information above, no you should not be worried. Of 1000000000 people, there will be 10000000 false positives (multiply by 1%) and 99 true positives. The rest will be negative (including one false negative, and assuming I did the arithmetic right which is not a given). Given that you test positive, the likelihood that you are, in fact, sick, is 99/10000000. Not bad odds...

The information about how much of the population actually has the disease is what's called a prior. Without a prior on Ahmadi cheating, we cannot make a posterior (the odds after considering the test, or the election results) prediction.

There are lies, damn lies, and statistics... but actual statisticians are pretty good at this stuff. They don't often do political polling though.

Re:The 1 in 200 bit is garbage

[skelterjohn]

I said exactly nothing false. Whether or not it is relevant to the topic on hand is left to the reader, but what I presented was just mathematic.

And, for what it's worth, this slashdotter is a PhD student in machine learning (responding to the GP's comment about 2 PhD students vs a slashdotter).

It's not all that competently done

[Anonymous Coward]

So, yes, they could manage this farce.

PS how did they manage to get the Shah of Iran in Iran in the first place? How did they manage to get Saddam set in power when the Shah was kicked out?

Manuel Noriega.

Grenada.

Cuba (pre Castro).

Many, many more.

If the CIA can't manage this demonstration, how did they manage all those others?

Re:I keep asking myself why we care about Iran?

[Curtman]

(Save the comments about the U.S. putting the Ayatolla into power, I already know.) But I keep asking myself, why should we care at all?

Because the U.S. put the the Ayatollah into power, and tried to prevent the revolution which overthrew the dictator that it saw as being friendly. But you already know that. And because the U.S. gave Saddam support while he used chemical warfare against Iranian civilians.

Those aren't the actions of a country that is fit to be world police. Those are the actions of a sociopath. Especially if you see no reason to care at all.