3 ms·

Not sure if dumb question: If they use the data you provide (such as your address) to search other data brokers, doesn't that potentially give the data broker

Not sure if dumb question: If they use the data you provide (such as your address) to search other data brokers, doesn't that potentially give the data broker MORE information than they already had on you? Do the companies in this space prevent this somehow? Edit: Lest people think this is somehow impossible otherwise - all it should take would be to search for just your name + location, get the query results, then filter on the client side. Which is exactly what a human would do for the brokers that have a "remove this entry" option when you see (presumably) yourself in the search results. However, this not only requires the data brokers to support such an API, but also requires the deletion services to actually put in the effort to do it this way for every broker they can, which seems nontrivial. Hence my question of whether these services make such an attempt at all.

notyourwork 3y ago
It seems to me like this is a core problem with the scummy nature of this business. I’d like to believe you’re weong but have trouble given the business model.
mattstir 3y ago
Not a dumb question at all. Yeah, in the process of finding you within a data brokers system and sending a removal request, they need to send that broker your personal data... it's a bit awkward. Optery, another PII removal service has a whole section about this in their privacy policy (section 7 of https://www.optery.com/privacy-policy/ https://www.optery.com/privacy-policy/): > Optery, Inc. must send your PII to the data brokers and information aggregators included in the Removal Lists... We cannot control, guarantee or warranty how these third-parties will treat your PII or what they will do with it.
- feedsmgmt 3y ago
  And you need to enter all of the information that you're trying to protect into one central location that is probably heavily targeted. These types of services never made sense to me.
- beyondd 3y ago
  Optery also has a Help Desk article on this catch-22 where in order to opt out of data broker sites, you must first tell them who you are, otherwise, how else would they know who to opt out: https://help.optery.com/en/article/what-information-does-optery-share-with-data-brokers-when-opting-me-out-1dxtj/ https://help.optery.com/en/article/what-information-does-opt...
  - hedora 3y ago
    They could use a bloom filter with some sort of a cryptographic hash. On a hit, the data broker could challenge them to compute a salted hash of the "matched" data. If the salted hash matched, the data broker would remove the data. I think the same algorithms that are used for password storage would work for this without modification (except the data broker would pick different salts during each session, and you'd send the hash over the network).
    - Jommi 3y ago
      its called a ZKP
    - politician 3y ago
      No company wants to implement this. I've been involved in efforts to use this approach with hospitals -- a perfect PII-preserving situation -- that went nowhere. We got it working with a startup once where we published the bloom filter to reduce the traffic load for the counterparty. Do you know what they did? They reverse engineered the filter by blasting it with every key and cached the result.
m3047 3y ago
Nothing is impossible in tech. (Rhetorical hyperbole!) But seriously let me give you an analogous example, with its pros and cons. DNS now has something widely deployed called "query name minimization". For no particular reason other than it made server's lives easy (which it does, as we will explain) the recursion process historically sent the actual qname (what was asked for) to each nameserver contacted. Much was made of this in recent years, that this leaked potentially important information to servers which demonstrably couldn't have the actual answer for the qname (even if they could provide a useful referral). Two flavors of qname minimization exist in the field. One flavor asks qtype A questions of the form "_.example.com" until it triangulates on the server with the answer; the other asks qtype NS questions (regardless of the actual qtype). (In case you've noticed a change in the mix of your DNS traffic.) In a nutshell, qname minimization asks questions which enable it to triangulate on the server which can potentially answer the question, before sending the actual question to it. A good rule of thumb is that with a cold cache qname minimization will result in nearly twice as many queries being issued / answered during the resolution process, assuming nothing goes wrong. Both of these approaches are prone to mistakes when servers don't conform to assumptions about how proper DNS should operate.
lancesells 3y ago
Could there be some sort of Robin Hood action to all of this? What if you took all the leaked data about millions of people and used that to opt out them out of all the various services that buy and then sell the data?
- gzer0 3y ago
  That is a possibility. Another scenario is one in which you sign up to a service like Optery and submit a non-existent individual with fabricated information for PII removal; after about a month or so, this fabricated individual started showing up as a possible person that lived at my address when I was trying to get a quote from Progressive. So, seems like somewhere in the midst of this process, one of the 240 brokers that Optery sends your information to get it removed, someone aggregated it, sold it to Progressive and in the underground realm of data brokers and buying and selling data, someone unfortunately (or fortunately?) is now targeting 'Paige Notfound' and 'Meg A. Byte'. I got the last laugh! :)
  - dataflow 3y ago
    Thanks so much for sharing this, I was wondering what would happen if I tried this. I guess this basically tells me to be weary of such services. Great info. P.S. Just a heads up that you may have basically revealed your address by sharing those fake names (though I haven't tried to search), unless you also made up those names just now for illustration...
    - gzer0 3y ago
      Thanks for looking out; those were not the actual names I used! I added those in for comedic effect ;)
andirk 3y ago
With an American SSN, one could dump 1,000 queries of numbers with only 1 of them being the client's actual SSN so the logs don't reveal as much. Still, though, it's a Catch 22 to find the thing you don't want found by using that thing.
footlose_3815 3y ago
It feels weird, but this is how background checks work, and how the current removal process for data brokers works. I can't think of other ways to verify yourself other than to verify yourself.
kanary 3y ago
Any 3rd party service or individual doing opt outs should limit data sharing as much as possible. Steps to do that include setting up email aliases, searching data in separate queries, using a proxy or VPN, verifying data exists before sending a data deletion request with all your pii in it, pushing back on any invasive requirement for govt ID... It's tempting to just automate sending a mass email to all the brokers with your full name, DOB, and address asking for deletion (some services actually do this - beware), but that exposes you to a bunch of new spam. I've been building Kanary for 4+ years (we're a removal service & YC grant recipient) and we take a conservative approach to each site. I wrote a bit more about why this matters: https://www.kanary.com/blog/dont-get-spammed https://www.kanary.com/blog/dont-get-spammed

notyourwork 3y ago

It seems to me like this is a core problem with the scummy nature of this business. I’d like to believe you’re weong but have trouble given the business model.

mattstir 3y ago

Not a dumb question at all. Yeah, in the process of finding you within a data brokers system and sending a removal request, they need to send that broker your personal data... it's a bit awkward. Optery, another PII removal service has a whole section about this in their privacy policy (section 7 of https://www.optery.com/privacy-policy/ https://www.optery.com/privacy-policy/): > Optery, Inc. must send your PII to the data brokers and information aggregators included in the Removal Lists... We cannot control, guarantee or warranty how these third-parties will treat your PII or what they will do with it.

feedsmgmt 3y ago
And you need to enter all of the information that you're trying to protect into one central location that is probably heavily targeted. These types of services never made sense to me.
beyondd 3y ago
Optery also has a Help Desk article on this catch-22 where in order to opt out of data broker sites, you must first tell them who you are, otherwise, how else would they know who to opt out: https://help.optery.com/en/article/what-information-does-optery-share-with-data-brokers-when-opting-me-out-1dxtj/ https://help.optery.com/en/article/what-information-does-opt...
- hedora 3y ago
  They could use a bloom filter with some sort of a cryptographic hash. On a hit, the data broker could challenge them to compute a salted hash of the "matched" data. If the salted hash matched, the data broker would remove the data. I think the same algorithms that are used for password storage would work for this without modification (except the data broker would pick different salts during each session, and you'd send the hash over the network).
  - Jommi 3y ago
    its called a ZKP
  - politician 3y ago
    No company wants to implement this. I've been involved in efforts to use this approach with hospitals -- a perfect PII-preserving situation -- that went nowhere. We got it working with a startup once where we published the bloom filter to reduce the traffic load for the counterparty. Do you know what they did? They reverse engineered the filter by blasting it with every key and cached the result.

m3047 3y ago

Nothing is impossible in tech. (Rhetorical hyperbole!) But seriously let me give you an analogous example, with its pros and cons. DNS now has something widely deployed called "query name minimization". For no particular reason other than it made server's lives easy (which it does, as we will explain) the recursion process historically sent the actual qname (what was asked for) to each nameserver contacted. Much was made of this in recent years, that this leaked potentially important information to servers which demonstrably couldn't have the actual answer for the qname (even if they could provide a useful referral). Two flavors of qname minimization exist in the field. One flavor asks qtype A questions of the form "_.example.com" until it triangulates on the server with the answer; the other asks qtype NS questions (regardless of the actual qtype). (In case you've noticed a change in the mix of your DNS traffic.) In a nutshell, qname minimization asks questions which enable it to triangulate on the server which can potentially answer the question, before sending the actual question to it. A good rule of thumb is that with a cold cache qname minimization will result in nearly twice as many queries being issued / answered during the resolution process, assuming nothing goes wrong. Both of these approaches are prone to mistakes when servers don't conform to assumptions about how proper DNS should operate.

lancesells 3y ago

Could there be some sort of Robin Hood action to all of this? What if you took all the leaked data about millions of people and used that to opt out them out of all the various services that buy and then sell the data?

gzer0 3y ago
That is a possibility. Another scenario is one in which you sign up to a service like Optery and submit a non-existent individual with fabricated information for PII removal; after about a month or so, this fabricated individual started showing up as a possible person that lived at my address when I was trying to get a quote from Progressive. So, seems like somewhere in the midst of this process, one of the 240 brokers that Optery sends your information to get it removed, someone aggregated it, sold it to Progressive and in the underground realm of data brokers and buying and selling data, someone unfortunately (or fortunately?) is now targeting 'Paige Notfound' and 'Meg A. Byte'. I got the last laugh! :)
- dataflow 3y ago
  Thanks so much for sharing this, I was wondering what would happen if I tried this. I guess this basically tells me to be weary of such services. Great info. P.S. Just a heads up that you may have basically revealed your address by sharing those fake names (though I haven't tried to search), unless you also made up those names just now for illustration...
  - gzer0 3y ago
    Thanks for looking out; those were not the actual names I used! I added those in for comedic effect ;)

andirk 3y ago

With an American SSN, one could dump 1,000 queries of numbers with only 1 of them being the client's actual SSN so the logs don't reveal as much. Still, though, it's a Catch 22 to find the thing you don't want found by using that thing.

footlose_3815 3y ago

It feels weird, but this is how background checks work, and how the current removal process for data brokers works. I can't think of other ways to verify yourself other than to verify yourself.

kanary 3y ago

Any 3rd party service or individual doing opt outs should limit data sharing as much as possible. Steps to do that include setting up email aliases, searching data in separate queries, using a proxy or VPN, verifying data exists before sending a data deletion request with all your pii in it, pushing back on any invasive requirement for govt ID... It's tempting to just automate sending a mass email to all the brokers with your full name, DOB, and address asking for deletion (some services actually do this - beware), but that exposes you to a bunch of new spam. I've been building Kanary for 4+ years (we're a removal service & YC grant recipient) and we take a conservative approach to each site. I wrote a bit more about why this matters: https://www.kanary.com/blog/dont-get-spammed https://www.kanary.com/blog/dont-get-spammed