CEP Senior Advsier Dr. Hany Farid writes: "In the past, tech industry giants such as Google have argued that it is pointless to block certain websites because they simply emerge under slightly modified names—thus leading to an endless whack-a-mole problem. This problem, however, can be addressed by tracking distinct markers in the underlying web-page code, text and imagery associated with specific sites. Similar approaches have proven effective in blocking everything from child sexual abuse to terrorism-related material."