Matthew Alexander Falder is an English convicted serial sex offender and blackmailer. Between 2009 and 2017, he coerced his victims online into sending him degrading images of themselves or into committing crimes against a third person such as rape or assault. He managed this by making threats to the victim by saying he would send their family or friends degrading information or revealing pictures of them if they did not comply with his commands. Falder hid behind anonymous accounts on the web and then re-posted the images to gain a higher status on the dark web. Investigators said that he "revelled" in getting images to share on hurtcore websites. The National Crime Agency (NCA), described him as "one of the most prolific and depraved offenders they had ever encountered."