Thanks, that's the first time I've heard the term.
Apparently Elon Musk tried this same technique at Tesla but "it backfired hilariously on the brilliant entrepreneur" [0,1]. According to Wikipedia [0]:
> After a series of leaks at Tesla Motors in 2008, CEO Elon Musk reportedly sent slightly different versions of an e-mail to each employee in an attempt to reveal potential leakers. The e-mail was disguised as a request to employees to sign a new non-disclosure agreement.
zero width is a good idea as engineers are less likely to leak info as they livelihood is affected by them, unless they are already trying to jump ship.
