As news editor for the independent magazine Caretas, Valenzuela battled, and survived, six closings of the magazine by repressive governments. She received multiple death threats due to her critical reporting, including some via the Internet. Valenzuela left the magazine to start a family then returned to journalism with her own television show, which was censured and closed at the end of 1998.
Valenzuela also wrote an expose on President Fujimori in 1998, after which she received threats. Fujimori's government, she said, does not allow research and criticism from the electronic media.
She continues to investigate those inside the government who obstruct democracy. "Journalists should keep themselves aware of the Power," Valenzuela said. "Power is always suspicious. Where Power is, research has to be done."