Kill List: Jay and Gal are employed to do three hits by a mysterious, wealthy man. Although they sign up willingly, one Blood Pact and several very strange experiences later, they try to bow out. They are then informed that their employer knows where their families live and will kill them if they don't complete it. Turns out this is because they are a pagan cult and are going to make Jay their new leader.
Thor: Ragnarok: The Grandmaster's gladiators are unable to leave due to having chips embedded in their flesh that shock them if they disobey. Nevertheless, the Grandmaster refuses to call them slaves and insists on calling them ?prisoners with jobs?.
Sorry to Bother You: The WorryFree corporation offers an employment deal of work, housing, and food for the rest of one?s life, with the caveat that one can never exit the deal. And they plan on mutating their workers into human-horse hybrids to make them into literal livestock...
Going Postal: Moist von Lipwig is a Boxed Crook offered a choice between employment as the new postmaster, or execution. A golem is assigned to assist him, and as an unstoppable retriever if he tries to run away.
We Sold Our Souls: Kris's old bandmate Terry sold his soul for fame and fortune. He got it - he's a multi-millionaire heavy metal rocker - but in return he has to feed Black Mountain with the souls of his fans. Black Mountain is never satisfied, regardless of how many it receives, and he can't ever be free or they'll kill him.
Sprawl Trilogy: Corporations often lock prominent scientists and top executives into ironclad contracts that never allow them to change jobs. Leading to an underground industry in "extractions" that are practically kidnappings (preferably with the target's cooperation), and countermeasures such as insulin pump implants loaded with addictive drugs or Synthetic Plagues.
Manga & Anime
Area 88: At the beginning, the protagonist is tricked while drunk by a jealous rival into signing a contract as a mercenary fighter pilot in a foreign civil war, and is forced to fight a three-year tour under threat of execution.
Spirited Away: Yubaba will employ anyone at her bathhouse who asks, but they must sign a contract that makes them forget their true name and binds them to service until they recall it.
The Magnus Archives: Employees at The Magnus Institute, or at least in the archives physically cannot quit their jobs, no matter how much they might wish to, except by gouging their eyes out.
Shadowrun: The mega-corps are so powerful they have sovereignty, and can enforce their own laws. It's pretty common for employment to be mandatory for life, with imprisonment, death or other punishments as a penalty for trying to quit. Extracting a (willing or unwilling) target to work for a new employer is a common and lucrative job for shadowrunners.
During the Age of Sail, the British Navy practiced impressment, the forcible rounding up and "employment" of people as sailors. Once the ship was out to sea, the men could either serve their term or try to swim back to England. It was eventually abolished after enough outcry arose over it being effectively slavery.
The UAE welcomes immigrants to come and find employment, and many do from surrounding poorer countries. Once there, they effectively become chattel of their employers. Their passports are taken away, and their employer is permitted to physically detain them and use threats of violence to enforce their service.