I'm a software developer who has been working on a yet-to-be released content filtering application. One of the filtering categories is of course pornography, and once upon a time I decided I was going to develop a pornographic image detector/classifier. That is to say, the program would load the image, perform some analysis of the image and classify it accordingly.

Anyone who has ever developed anything like this knows that you need a significant base of source material from which to derive your original classification models. So, I installed DownloadThemAll into Firefox and started punching in some nasty terms plus the words "Tumblr". Material collected.

I ended up having thousands of images, both pornographic and non-pornographic so that the algorithm could extract features to make accurate classifications. However, after some time of developing and having never actually personally analyzed these thousands of images, my wife and I discussed the very real potential that something unspeakable may have been on one of these sites that I scripted to have all images dragged down from. So, I ceased development destroyed everything I had collected, deciding the risk of inadvertently having such filth was definitely not worth it.

So my question is, would I be liable if something had of been there? How can I go about such research while protecting myself (if at all)? The last thing on earth I'd want in life is being thrown in a headline next to Jared Fogle, with the only excuse being "I didn't know! It was for science!"

Google actually copies and stores image results on their own servers. So they can and do have instances where illegal explicit material is copied and stored on private servers. How are they covered from liability or possession?

  • related law.stackexchange.com/questions/3446/sexting-and-age
    – Dale M
    Commented Sep 24, 2015 at 0:44
  • 2
    Depends on jurisdiction. Canada has a "Public Good" defense that might be applicable: en.wikibooks.org/wiki/Canadian_Criminal_Law/Offences/…
    – user6726
    Commented Apr 10, 2016 at 19:20
  • @user6726 oh nice, thanks for sharing.
    – user900
    Commented Apr 10, 2016 at 21:47
  • Not an answer, but if you ever decide to resume this line of work in the future, it may be prudent to have your lawyer approach the authorities who deal with this matter, tell them that you are working on an automated tool to identify pornographic content, and make your concerns known. It may be that they are interested in a tool that can automate the process of identifying illegal images, which would help in their efforts to combat that vile traffic, and you might even gain their aegis in this endeavor.
    – EvilSnack
    Commented Jun 4 at 2:49

1 Answer 1


As discussed in Sexting and age, in NSW there are a number of defences, the most relevant being:

  • Innocent possession:the defendant did not know, and could not reasonably be expected to have known, that he or she possessed ...
  • Approved research: was necessary for or of assistance in conducting scientific, medical or educational research that has been approved by the Attorney General in writing ...

From the circumstances, you could avail yourself of the first defence. If you had sought prior approval (which you haven't) then the second would be open to you.

  • Thanks, I guess I should investigate getting some sort of research approval, however that works for where I am.
    – user900
    Commented Sep 24, 2015 at 5:24

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