Thousands of TV production staff, presenters and voice-over artistes are in hiding following death threats issued by the self-proclaimed "TV Repair Man."
Stars like Masterchef Presenters John Torrode and Gregg Wallace and loveable ITV pair Ant & Dec are believed to be under police protection.
Work on most daytime programmes has been suspended temporarily while security arrangements are examined by terrorism experts.
The chaos has been caused by threats in a set of documents delivered to EIF News & Features at their West London HQ.
The papers, contained in a cover featuring a smashed television set, feature lists of programmes, their presenters, voiceover artistes, production staff and companies.
Subdivisions include "Quizzes," "Home Makovers," "Relocation" and "Reality."
In a covering 30-page statement, The TV Repair Man writes: "TV is broken and must be repaired. I intend to mend programming by removing the villains who have brought us to this pass.
"The criminals-in-chief are the purveyors of the so-called daytime schedules in which the rules of game shows are constantly re-explained or the viewer is repeatedly told what he has already seen just short minutes previously."
Daytime shows singled out include Put Your Money Where Mouth Is which features experts competing to buy and sell antiques for the greatest profit.
TV Repair Man is particularly angry at the voiceover man: "Soi-disant narrator Stephen Taylor Woodrow must die. His sing-song delivery is like fingernails on a blackboard."
But daytime TV is not alone. TV Repair Man is also threatening to put an end to Masterchef - "celebrity or otherwise."
"Shouters Torrode and Wallace must stay off the air from henceforth or I will not be responsible for the repercussions.
"Also, voiceover succubus India Fisher must cease and desist her ridiculous efforts at breathy sexuality. It simply does not suit spatchcocking a chicken, for Heaven's sake!"
EIF N&F immediately passed copies of the document to Scotland Yard and police forces around the country have been alerted.
A police spokesman told us: "We are working closely with production staff to protect them and their families and to try to get programme-making back on track as soon as possible."
She confirmed that shows such as Escape to the Country, House Gift, Cash In The Attic, Wanted Down Under and To Buy Or Not To Buy were among the programmes affected by the threats.
"There are so many programmes on the list - all the reality shows, daytime quizzes and what-have-you, we are quite stretched. It's possible we may not be able to save everyone..."