Labels that put people in that special zone. False positives would be a problem with all of the following:
(What if they really aren't sick - after a few hours with the other detainees they sure will be!)
(What if they are put in quarantine by accident?)
(What if police/military/government puts their own enemies in quarantine)
- Sex offenders
(True positive? Great. Accidental or deliberate false positive? People in society who hear about it may tend to shy away from defending the person in case the anti-midas touch (thanks Wolfhounds) of perceived filth also rubs off on them. So it is an especially dangerous label if a false positive gets stuck with it.)
- Taliban/Al Qaeda
In the early days of the Afghanistan war, people were rounded up and sent to Guantanamo. The person who apprehended someone else got a bounty. This is another case of "just wait, after a few days in the slammer they will be!" It's Bob Wright's argument about radicalization. If they weren't pissed off before, they will be after a decade of false imprisonment.
Disclaimer: I like for true positives to be arrested. Good intelligence work, done well and honestly, is a good thing. The problem arises when you take for granted human fallibility and mistakes, and soon you are arguing over how many mistakes are OK for the sake of the goal. See the post about killing 49% to save 51%.
Pretty much every post on this blog is going to beat this dead horse over and over. :) I'll add to this list when I think of more.