Netflix Prize 2 Cancelled Due to a Lawsuit and FTC Inquiry

http://blog.netflix.com/2010/03/this-is-neil-hunt-chief-product-officer.html

by gaika • 16 years ago

103 71 16 years ago

blog.netflix.com

nlabs20• 16 years ago

How does sharing the Netflix data violate privacy? With the hundreds of thousands of records it would be difficult to trace information to an individual. The US needs more engineers and fewer lawyers.

gaika• 16 years ago

There's a way to identify individuals in the raw data:

http://userweb.cs.utexas.edu/~shmat/shmat_oak08netflix.pdf http://userweb.cs.utexas.edu/~shmat/netflix-faq.html

nfnaaron4• 16 years ago

It's almost always surprising just how much private data can be exposed after data has been "anonymized."

When you're using private data in any public way, or even with "partners or affiliates," you need to be very careful, watchful and responsive.

nlabs20• 16 years ago

Interesting thanks for the link. However, seems like you need to be able to cross-correlate with another database in order to de-anonymize. If netflix made a good faith effort to protect privacy, how are they liable?

toby• 16 years ago

I get "Forbidden" for both those links. Are there any other links to those papers? I hadn't heard of this result and I'm very curious.

davidu• 16 years ago

http://cc.bingj.com/cache.aspx?q=%22shmat+oak08netflix+pdf%2...

pronoiac• 16 years ago

Some people from the first dataset were deanonymized. Given age, gender, & zip code is enough to identify 87% of the US.

See http://arstechnica.com/tech-policy/news/2009/09/netflix-priz... and its links.

nlabs20• 16 years ago

Yes the issue is Netflix's liability. The reason it can be de-anomized is because people reveal more info in some other database (for example idbm) - if people willingly reveal more info in some other db, is that netflix's fault?

nopassrecover2• 16 years ago

I'm assuming you mean given name - why would this be included in the data set in the first place? Is there some significant correlation between names and movie preferences?

raganwald5• 16 years ago

It seems there are enough engineers, or at least there are enough to reverse the anonymization and reveal details that customers rightly considered private.

"Difficult" to de-anonymize is not enough. It must be impossible, and the burden of risk must be on Netflix, not the customer. We're sympathetic in this case because the contest is innovative and interesting. Imagine a slightly different story. In this one, the FBI asks Netflix for "anonymized" information, then de-anonymizes it and starts wiretapping people considered "suspicious." I think we would be rightly appalled at the idea of the government monitoring the movies we watch, and we would criticize anyone handing over the information they need to do it without asking or notifying us.

It's the same thing here, and Netflix should ensure opt-in with full disclosure of the potential for de-anonymization for the same reasons.

When I sign up for a service, I don't expect the vendor to publish data of my transactions to the entire world, even if they claim it is anonymized.

nlabs20• 16 years ago

I agree. (although Id still rather see more engineering and less lawyering). Netflix does need to get people to opt-in.

evgen• 16 years ago

Netflix is also facing problems because there is a specific law (the Video Privacy Protection Act of 1988) that makes it illegal for them to reveal data that could be linked to service subscribers. In this case the burden of proof would fall on Netflix to prove the dataset could not reveal a single link between subscriber and rental history.

cdavid• 16 years ago

The point is that it is actually fairly easy to trace information back to a user. People who are not familiar with this kind of data just don't realize how little you need to uniquely identify someone.

I am a little surprised to see that people who are generally uproar against companies not respecting privacy think it is perfectly ok to do it if it is for "science".

This is one of the big reasons why academics cannot release data BTW, especially in the social science: anonymizing data almost inherently means destroying valuable information.

tbgvi2• 16 years ago

Another case of lawsuits stifling innovation.

And I agree with one of the comments on that post - why doesn't Netflix have people opt-in to have their data anonymized and used for this purpose?

Edit: replaced bureaucracy with lawsuits

nlabs20• 16 years ago

good idea...opt-in and we can improve our recommendations to you.

People worried that some geek will find out they watched Who's the Boss reruns will miss out.

nfnaaron4• 16 years ago

I think bureaucracy had little to do with it. As I recall, the first Netflix contest did indeed expose private, and sometimes embarrassing, information.

This was a privacy issue, and something legitimate to address.

nlabs20• 16 years ago

privacy issues dont necessarily need to be dealt with by lawsuits. Most lawsuits are about money.

sh1mmer• 16 years ago

Right, but I find it astonishing that it was necessary to cancel the competition altogether.

I find it surprising that there wasn't a middle-ground which anonymized or didn't include personally identifying information.

I feel the lack of a middle-ground is probably due to the lawsuit plaintiffs refusing to back down (presumably for financial gain) and thus causing Netflix to hedge their risk.

tel• 16 years ago

It breaks simple random sampling meaning that you're optimizing purely for some unknown subset. That becomes a problem when someone someone realizes that Netflix is spending millions of dollars to have a recommendation engine that ends up being racist.

wingo2• 16 years ago

While it's not entirely the same situation, perhaps you should read up on the http://en.wikipedia.org/wiki/AOL_search_data_scandal.

mhb• 16 years ago

why doesn't Netflix have people opt-in to have their data anonymized and used for this purpose?

Selection bias?

ntoshev• 16 years ago

Selection bias would mean people who opt in get better recommendations... sounds like a good incentive and a virtuous circle to me.

nlabs20• 16 years ago

selection bias would only be a concern if you were trying make inference on all netflix customers (not just the ones that opt-in).

nfnaaron4• 16 years ago

Plus one to Netflix for making this the first sentence:

"This is Neil Hunt, Chief Product Officer for Netflix."

No vague hiding behind an unidentified team or blog. A person has chosen to identify himself with the decision, and the company chose to present it that way.

The general tone is also positive. This is a good way to communicate.

Contrast with Amazon's anonymous whine on their kindle blog when they gave in to MacMillan. Not signed by a person, not even "the team." And full of blame and "you'll see!"

http://www.amazon.com/tag/kindle/forum/ref=cm_cd_et_md_pl?_e...

smackfu• 16 years ago

True, although I prefer if the real person has a real job title.

barmstrong• 16 years ago

I agree that a person identifying himself was admirable. But I'd rather he identified himself, and then went on to say how he really felt about it (I'm assuming here they were more disappointed to close it then he let on).

This is professional - but it also lacked much backbone.

smakz• 16 years ago

Comparing Amazon's official communication with customers to Netflix I think Amazon wins.

Looking at Netflix's blog they have 3 posts for the entire year.

Looking at Amazon's discussion forums, there are a swath of official announcements, including one that informs customers how to access 2 million free books outside of Amazon.

Sure, having a name in front of the post is nice I guess, but in terms of consistent and valuable customer communication I think Amazon wins. Also here's an example of an apology from Bezos himself

http://www.amazon.com/tag/kindle/forum/ref=cm_cd_ef_tft_tp?_...

froo• 16 years ago

Dear Lawyers,

Lame

Regards

The Tech Community

nlabs20• 16 years ago

Netflix Prize 3: How to create a meaningful database that is impossible to de-anonymize.

mortenjorck• 16 years ago

Funny, yes, but I honestly think they should consider this.

gwern• 16 years ago

It's been a while since the flurry of de-anonymizing data papers back in 07-08, but my takeaway impression was that you can't truly de-anonymize large datasets without destroying its utility.

stuntgoat• 16 years ago

Why not just have the customer opt-in/out of 'algorithm participation' per movie selection?

Likely, Netflix has the power to start it's own social network platform based on it's existing users' movie preferences. Some user's might be proud to say that they rate specific movies highly, and correlate to particular algorithms based on collective opinions.

For instance: 'Click here to add user X's preferences to your algorithm for Y genre'

jmonegro• 16 years ago

You mean 'inquiry'

raheemm• 16 years ago

What is the protocol for which words to begin capitalized in a headline?

sp3322• 16 years ago

I think the title used to say "enquiry."

tjogin• 16 years ago

Is not "inquiry" and "enquiry" identical in all respects except spelling?

sp3322• 16 years ago

Enquiry is asking someone else a question. Inquiry is looking into it yourself.

Netflix Prize 2 Cancelled Due to a Lawsuit and FTC Inquiry

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