I remember Facebook announced a while ago that it would scan its Facebook chat for "criminal activity", to give the info to the police.
http://news.cnet.com/8301-1023_3-57471570-93/facebook-scans-...
Where is the line drawn? And will we know where it's drawn? Stuff like this makes me trust "cloud computing" less and less. I hope Google and others realize this, before it's too late (for them) to change course.
I can take a guess where this is going, though, if NSA's actions are any indication - there won't be a line anymore, if they (government/corporations) are left alone to continue with stuff like this. Every single crime, no matter how small and insignificant, will be reported to the police, thanks to the mass surveillance capabilities of the alliance between NSA/government and corporations. After all, when "safety" is the ultimate goal, above all else, that outcome is all but inevitable.
It's already started:
http://falkvinge.net/2013/11/24/nsa-mass-surveillance-has-al...
The line was crossed a long time ago when the Law was treated as an opinion. This cultivated a "let's see what we can get away with" attitude which is now starting to unfold before the world stage.
For more info, see:
https://en.wikipedia.org/wiki/John_Yoo
http://www.law.cornell.edu/uscode/text/18/2258A
To my knowledge, Google wasn't required to check its hosted files for specific image hashes: "Nothing in this section shall be construed to require an electronic communication service provider or a remote computing service provider to— (1) monitor any user, subscriber, or customer of that provider; (2) monitor the content of any communication of any person described in paragraph (1); or (3) affirmatively seek facts or circumstances described in sections (a) and (b)."
But once they did, they were required to report the results. Any privacy concerns are waived as an "[exception] for disclosure of communications" as part of 18 USC § 2702: "Voluntary disclosure of customer communications or records". http://www.law.cornell.edu/uscode/text/18/2702
It's not surprising that Google is affirmatively scanning its servers for child porn, as they have a long history of providing assistance to NCMEC:
http://googleblog.blogspot.com/2008/04/building-software-too...
http://googlepublicpolicy.blogspot.com/2012/01/crowdsourcing...
"$1 Million from Google to Fight Child Sexual Exploitation Received by the National Center for Missing & Exploited Children" http://www.missingkids.com/news/page/4898