Secrets and Content Warnings
The GM, when writing the scenario, has a huge responsibility to their players when writing and assigning Secrets. Typically the Secrets are written and prepared ahead of time, to fit the scenario. Often times the players will have little to no say in their creation, especially in con games or one shots with players unknown to the scenario creator. This means that the players have to have a lot of trust in the GM to hand them a Secret that won't ruin the game for them.
The replay in the core book depicts a situation where there is some brain washing. Similar situations where players may perceive a loss in agency or consent for their character, or where players may have some past trauma, are not good Secrets unless cleared with the player first. Pitch the scenario to the players before the game, including a content warning.
I recently started a game online with a couple players I know personally, and a couple I didn't. Without paying much attention to whom I was assigning Clans/Missions/Secrets, I handed a Secret involving brainwashing to a woman I I'd never met. She privately messaged me before the game saying she was uncomfortable but was willing to work with it. I read the 2nd half as permission to keep the Secret but in the end she decided it was too much and dropped the game. I could have just as easily changed a few things around to make her comfortable and welcome, and I regret that I did not.
If a player ever expresses discomfort with a Secret or Mission, change it. Change your scenario if you have to to make room for any necessary substitutions.