Child Sexual Abuse Material Online: Detection Myths vs Fact

Separating fact from fiction on the detection of child sexual abuse material online.

Public debate about child sexual abuse material (CSAM) detection is often dominated by myths, misunderstandings and fears about how technology works online. 

While misconceptions spread, children continue to be abused, and criminal material continues to circulate online on an industrial scale. 

Discover the facts behind online child sexual abuse material detection. Watch our myth-buster video to learn how privacy safeguards work: what they are, how they work and why they are essential to protecting children, victims and survivors online. 

From hash-matching and privacy protections to encryption and upload prevention, these videos address some of the most common questions and concerns surrounding proactive detection technologies. 

Watch the video below to learn more about: 

  • How hash matching works;
  • Privacy and safeguards;  
  • Encryption and upload prevention;  
  • Unknown CSAM detection;  
  • False positives and human review;  
  • Why proactive detection matters. 
IWF Chief Technology Officer, Dan Sexton, speaks with Dr Ahmed Abdullah, a Cybersecurity Researcher at Manchester Metropolitan University.

What is CSAM detection? 

CSAM detection refers to a range of technologies and tools used to identify, report, block and remove child sexual abuse material online. 

Different technologies are used for different purposes, including: 

  • detecting known CSAM using hash matching;  

  • identifying previously unknown abuse material;  

  • detecting grooming and suspicious behavioural patterns;  

  • enabling user reporting and moderation;  

  • preventing the re-upload and sharing of illegal content.  

Many of these technologies are already widely used across the digital ecosystem in other contexts, including cybersecurity, fraud prevention, malware detection and blocking harmful websites. 

Why proactive detection matters 

Every time child sexual abuse material is re-uploaded or reshared online, victims and survivors can be revictimised. 

Some abuse material remains in circulation for decades. 

Blocking the spread of CSAM is not pointless because offenders may move elsewhere. Every barrier placed in front of offenders reduces circulation, limits harm and helps narrow the spaces where abuse material can be shared. 

No single technology will solve the problem alone. But proactive detection remains an essential part of creating a safer online environment for children. 

Our Mythbusters

Dan Sexton is the Internet Watch Foundation’s Chief Technology Officer. Dan’s role involves securing highly sensitive data and leading a dedicated team building resilient and efficient systems to support IWF’s work both within the office and in the cloud. He is also responsible for the compliance and quality assurance team ensuring that highest standards of work and data quality are adhered to when creating our globally-trusted datasets. 

Dr Ahmed Abdullahi is a Research Associate at the Privacy, Security and Trust (Pri-SeT) Research Lab, Manchester Metropolitan University, where his research spans cybersecurity, cyber-physical systems, cryptography, and privacy-preserving technologies. He brings an independent academic perspective to the question of how platforms can detect and remove CSAM without compromising the privacy rights of users and is a co-author of the Alan Turing Institute's CETaS report on privacy-preserving moderation of illegal online content. 

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