The question of what Google might search for, using what hashes, on whom, why and when, and how, comes to mind.
Google didn't "look at pictures". It had a database of known child porn images for which it computed hashes or signatures, which then could be checked, presumably of attachments in emails. This lets Google avoid the matter of "we looked at your specific images". It also means that your random personal photos aren't going to be examined (though their hashes are computed, and possibly retained).
The hashing approach could apply to other aspects of email as well, though. Google could, perhaps, be encouraged to maintain a set of hashes corresponding to musical performances (it uses a similar technology AFAIU for YouTube copyright determination). Or of books. It could even take tuples of word sequences within email, compute hashes, and compare these with known word strings, forwarding relevant information to interested parties should certain sequences occur.
All without "reading" your email.
Where do you draw the line?
Is it "think of the children"?
Do we extend this to "think of the terrorists"? How about seeking out white-collar crime -- a set of account numbers, or key phrases, or transaction sequences?
Or do we look for drugs crimes? Or gang activity? Or political insurrection?
Can different national jurisdictions come up with their own sets of keywords? Say, those associated with specific religious or ethnic groups and activities? Uighurs, or Tibetan independence movement? Boko Haram? Aum Shinrikyo? Provisional IRA? Shining Path? ELF and PETA? Bangsamoro Islamic Freedom Fighters?
Because those are all possible with slight variations on the methods described here.
Or how should (or must) Google respond if users employ encryption to defeat such attempted detection?
Google didn't "look at pictures". It had a database of known child porn images for which it computed hashes or signatures, which then could be checked, presumably of attachments in emails. This lets Google avoid the matter of "we looked at your specific images". It also means that your random personal photos aren't going to be examined (though their hashes are computed, and possibly retained).
The hashing approach could apply to other aspects of email as well, though. Google could, perhaps, be encouraged to maintain a set of hashes corresponding to musical performances (it uses a similar technology AFAIU for YouTube copyright determination). Or of books. It could even take tuples of word sequences within email, compute hashes, and compare these with known word strings, forwarding relevant information to interested parties should certain sequences occur.
All without "reading" your email.
Where do you draw the line?
Is it "think of the children"?
Do we extend this to "think of the terrorists"? How about seeking out white-collar crime -- a set of account numbers, or key phrases, or transaction sequences?
Or do we look for drugs crimes? Or gang activity? Or political insurrection?
Can different national jurisdictions come up with their own sets of keywords? Say, those associated with specific religious or ethnic groups and activities? Uighurs, or Tibetan independence movement? Boko Haram? Aum Shinrikyo? Provisional IRA? Shining Path? ELF and PETA? Bangsamoro Islamic Freedom Fighters?
Because those are all possible with slight variations on the methods described here.
Or how should (or must) Google respond if users employ encryption to defeat such attempted detection?