Big Brother had multiple ways of knowing who was rebelling against him by the updated
technology. The Thought Police is like the government they will know if you are trying to rebel against the party they are authorized to read your thoughts and see every movement. Telescreens are Big Brother watching you there was one in the room that Winston and Julia had gotten. Hidden microphones are everywhere. The only time they talk about passports was when a patrol asks for Winston's passport are the terminal station going to Mr. Charrington. Being erased from the world not being able to have any thought od Oceania is vaporization. Room 101 is different from everybody's else's is your greatest fear the point of room 101 is to ensure the final stage of reintegration acceptance.