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> Although the company claims it is all “non-personally identifiable data”, according to its website this surprisingly includes not only IP but the globally uni

by kawsper 14y ago

> Although the company claims it is all “non-personally identifiable data”, according to its website this surprisingly includes not only IP but the globally unique MAC addresses. Enough with the scare tactics. A Mac adress is not, in any way, globally unique.

daxelrod 14y ago
Isn't a MAC address supposed to be unique, though?
- kawsper 14y ago
  They are supposed to, but talk with any sysadmin or a guy hosting a big lan-party and you will know that, that isn't the case. I have hosted several 300-400 person lan-parties and there is always two or three machines with the same MAC-address. A MAC-address is somewhat unique, but it happens that manufactures re-use the address twice or more. I have a feeling that cheaper brands do it more, but I have nothing to back that up. There is a discussion here that backs up my claim: http://superuser.com/questions/268006/are-mac-addresses-unique-when-coming-out-of-the-factory http://superuser.com/questions/268006/are-mac-addresses-uniq...
jakobe 14y ago
Yes it is. Every network ethernet adaptor or wifi chip has a unique MAC address.
- kawsper 14y ago
  In a perfect world that is, and on your home network you would not see any issues. Take 400 computers and 2 of them will have the same MAC-address and you have DHCP-problems. http://superuser.com/questions/268006/are-mac-addresses-unique-when-coming-out-of-the-factory http://superuser.com/questions/268006/are-mac-addresses-uniq...
fennecfoxen 14y ago
Excuse me. As a rule, a MAC address is a decent approximation of globally unique, certainly good enough to identify a single computer for advertising purposes. If you have a MAC address and it's not globally unique, it's defective and out of spec. Which isn't to say duplicates never happen (ultra-cheap rip-off network cards, virtual machines, reprogramming your hardware manually, etc), but... there's a reason they go through the rigamarole of partitioning out different OUI blocks to different network equipment vendors.
- kawsper 14y ago
  In my experience as a lanparty organizer duplicates happens a lot, way more than I would like.
jordan0day 14y ago
Just because it's not unique doesn't mean it's not personally identifiable. For instance, you can quite often uniquely identify a person given their date of birth, gender, and zip code, none of which are nearly as unique as a MAC address[1]. Even the combination of these factors results in < 2 billion unique permutations, whereas the MAC address space numbers in the hundreds of trillions. That means, given a MAC address, I can narrow narrow down the "who" to a fairly small set of people. Add in even one other piece of scraped info, and you've got a pretty high level of uniqueness. [1] http://godplaysdice.blogspot.com/2009/12/uniquely-identifying-people-by-birth.html http://godplaysdice.blogspot.com/2009/12/uniquely-identifyin...
illuminate 14y ago
It is not. Combined with other factors, it can certainly be considered reliably unique.

by kawsper 14y ago

daxelrod 14y ago

Isn't a MAC address supposed to be unique, though?

kawsper 14y ago
They are supposed to, but talk with any sysadmin or a guy hosting a big lan-party and you will know that, that isn't the case. I have hosted several 300-400 person lan-parties and there is always two or three machines with the same MAC-address. A MAC-address is somewhat unique, but it happens that manufactures re-use the address twice or more. I have a feeling that cheaper brands do it more, but I have nothing to back that up. There is a discussion here that backs up my claim: http://superuser.com/questions/268006/are-mac-addresses-unique-when-coming-out-of-the-factory http://superuser.com/questions/268006/are-mac-addresses-uniq...

jakobe 14y ago

Yes it is. Every network ethernet adaptor or wifi chip has a unique MAC address.

kawsper 14y ago
In a perfect world that is, and on your home network you would not see any issues. Take 400 computers and 2 of them will have the same MAC-address and you have DHCP-problems. http://superuser.com/questions/268006/are-mac-addresses-unique-when-coming-out-of-the-factory http://superuser.com/questions/268006/are-mac-addresses-uniq...

fennecfoxen 14y ago

Excuse me. As a rule, a MAC address is a decent approximation of globally unique, certainly good enough to identify a single computer for advertising purposes. If you have a MAC address and it's not globally unique, it's defective and out of spec. Which isn't to say duplicates never happen (ultra-cheap rip-off network cards, virtual machines, reprogramming your hardware manually, etc), but... there's a reason they go through the rigamarole of partitioning out different OUI blocks to different network equipment vendors.

kawsper 14y ago
In my experience as a lanparty organizer duplicates happens a lot, way more than I would like.

jordan0day 14y ago

Just because it's not unique doesn't mean it's not personally identifiable. For instance, you can quite often uniquely identify a person given their date of birth, gender, and zip code, none of which are nearly as unique as a MAC address[1]. Even the combination of these factors results in < 2 billion unique permutations, whereas the MAC address space numbers in the hundreds of trillions. That means, given a MAC address, I can narrow narrow down the "who" to a fairly small set of people. Add in even one other piece of scraped info, and you've got a pretty high level of uniqueness. [1] http://godplaysdice.blogspot.com/2009/12/uniquely-identifying-people-by-birth.html http://godplaysdice.blogspot.com/2009/12/uniquely-identifyin...

illuminate 14y ago

It is not. Combined with other factors, it can certainly be considered reliably unique.