An engineer and former Facebook executive who put the founder of Facebook on the ropes in the eyes of the whole world with his testimony in the US Senate. His name is Arturo Béjar and he was hired by Mark Zuckerberg to design Facebook's user protection tools. Three years ago, this former senior official became a nightmare for Meta, owner of Facebook, but also of Instagram and WhatsApp. After realizing that the company was ignoring the damage it causes to the users of its networks, Béjar decided to tell what he knew and could prove. The result was that Mark Zuckerberg testified before a US Senate committee and was forced to apologize to the victims of his networks.