Hundreds of staff returned to work after staying away on Wednesday in protest against criminals operating at Paris's famous museum, the Louvre. Many tourists waited patiently to see its treasure trove of masterpieces, which include Leonardo da Vinci’s Mona Lisa and the Venus de Milo. Instead, they had to be satisfied with just taking pictures of the iconic pyramid outside the museum. The museum was closed all of Wednesday after hundreds of workers went on strike to protest against pickpockets. These organised gangs often include young children, who do not have to pay to enter the museum. Al Jazeera's Anu Nathan explains.