Adding to the current labor strife in the TV and film industries, employees of the MTV Networks staged a walk-off Monday to protest recent changes in health and vacation benefits for freelance employees. Many of the employees affected, however, insisted that they have actually worked full-time and that Viacom, MTV's corporate parent, keeps them on their books as freelancers in order to avoid paying them the same benefits. The New York Times reported today (Tuesday) that employees participating in the impromptu demonstration filled almost the entire block in front of Viacom's headquarters on Broadway.