Big tech and media organisations (eg Google or any image or video hosting service provider), process and filter a huge amount of illegal child porn everyday. They even have employees doing this, watching and censoring child porn that is. Isnt watching it, even in order to censor it, according to such laws, illegal? Also while the material remains in the servers, isnt the company liable for possession ?
In Greece for example, the law is rather simple and doesnt cover such cases.