A recent move by technology giants Google and Microsoft to prevent users from searching for child pornography online is a "blunt and ineffective tool and can easily be circumvented", a global professional body of engineers said.
Several Twitter accounts have been closed after they were revealed to contain disturbing images of child abuse.
A senior British government official, responsible for security at the Buckingham Palace and who was also part of an anti-terrorism unit, has been charged with making indecent images of children.
Day in Pics: 1st February
Showbiz World - February 1, 2015
Playboy Super Bowl XLIX Party