We do get some feedback on Google's image results and find that the feedback is all related to "racy" images and not outright nudity or pornography. Google does a great job of filtering out the inappropriate images that contain nudity or pornography. However, you can help Google make their results better by filing a report with Google: https://www.google.com/webmasters/tools/safesearch?pli=1.
Regarding filtering; I will share with you how it works “under the hood:”
- We enforce Google SafeSearch: This is the first level of filtering that is operated by Google. Google does a decent job of removing pornography but still allows some racy images such as lingerie and bikinis. In the near future, we are going to block all other search engines under a custom category called “Unsafe Search Engines” and only allow Google to be the default search engine as we had been getting some complaints from users that they can use a search engine like Ask (where we can’t enforce SafeSearch) to see inappropriate images.
- Then we have our own database of millions of sites that contain inappropriate material and these are blocked quickly. Example: If you search Google for Victoria Secret, you will see the images and link to the Victoria Secret website. And if you click on the link to the Victoria Secret website, we will block it as Pornography.
- Then there are new sites coming up all the time, for these, we use a URL categorizing service and check to see if that new site belongs to a category that we block. If so, we then block it and add it to our own database. This happens in milliseconds so you actually do not notice this as a user.
- Then, we have our own “Prone to Porn” category which blocks sites that are normally good but have unfiltered access to pornography, like Twitter, Tumblr, Imgur, Reddit and even Pinterest.
- Finally, robots make mistakes with their algorithms so we have a fast response to customers and edit categories and block sites manually.