Serge Leroy made a very interesting movie in 1975 :"La Traque" .It was followed by a more conventional effort :Les Passagers" ."Attention Les Enfants Regardent" is some kind of "Home Alone" for adults ,based on an American best-seller which did not interest anybody on the other side of the pond..Delon made a lot of rubbish in the seventies (with notable exceptions of course: "Traitement De Choc" "Monsieur Klein" and "The Assassination of Trotsky" ) but he made this one a winner .He portrays a shady man ,who knows what the children did (that summer?) .And what they did is simply bring about their nanny's death.
This is not a family movie,it's a cruel work which shows that children are not so naive that people generally think.And the stranglehold TV has on them ,nobody can deny it : the heroes are simply living one of the stories they saw in their favorite program.But the famous four (Le Club des Cinq) it isn't!