Former Nickelodeon stars protested outside the network’s Burbank, California, offices, RadarOnline.com has learned. The protest was led by former Zoey 101 star Alexa Nikolas and followed the release of Investigation Discovery’s shocking documentary Quiet on Set: The Dark Side of Kids TV, which uncovered rampant sexual abuse at the network during the ’90s and 2000s. On Tuesday, Nikolas and others gathered outside the Burbank studios. Protestors held photographs of Nickelodeon executives accused of fostering a toxic environment and enabling abusers, while the crowd chanted, “Protect survivors, n…