So one of the sites I use frequently for anime artwork finding purposes got taken offline because a Canadian anti-child abuse organization used it to reverse image search CSEM images, then reported the site for temporarily hosting CSEM, even though it was because of their badly coded crawler searching for it.
This post will hopefully make the situation a bit clearer for everyone. Most of this info has been posted in one place or another already, but I will attempt to consolidate the important bits as I recall them. I have effectively zero visibility into the operation of cybertip.ca or Project Arachnid (their crawler), so this is based on what I can tell from my end. I have not used this blog in many years, but it’s the easiest way I can publish this info now.
To start with, I do not believe they are acting maliciously, and they do not seem to be intentionally using the site to search for images. They are just following links. Dangerous links which spread CSAM (Child Sexual Abuse Material), links which they should be smart enough not to follow, but ultimately, still, just following links. From what I understand, these links primarily come from image boards and such which helpfully add them next to all posted images. This is great for users, as the links allow for quick and easy source lookups of interesting images as you come across them:
The current situation started in the afternoon on the 31st of March when our host received the first CSAM notification and promptly sent it over to us for review. At the time, I was traveling, and not online as often as usual so the report went unnoticed. Around the same time, the host of iqdb.org - another anime reverse image search engine - also started receiving similar notices. Likewise, they forwarded them to the site’s operator, but unfortunately the emails wound up in spam and were not immediately noticed. More reports continued coming in over the course of the afternoon and night. I finally noticed them in my email when I came back online later that night.