The co-founder of social networking site Ask.fm told ITV News he believes David Cameron "did not have all the information about the case" when he urged parents to boycott "vile sites" following the death of cyberbullying victim Hannah Smith.
Klavs Sinka said he believed the Prime Minister "hadn't really researched" the case before he made his comments.
He continued, "He was probably caught on the street in an interview similar to this and made a comment without having the full information about this case."
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Julian Cadman, who is thought to have dual British-Australian nationality, became separated from his mother who was injured in the attack.
Wayne Rooney and his wife Coleen are expecting their fourth child, the couple have announced.
As the silence came to an end the crowd began to applaud and people shouted "I am not afraid!" in defiance of the attacks.