@dancingtreefrog @vrek @capitainesam I think you're describing Orson Scott Card's "Dogwalker," which involves intuiting a password but failing to realize that the target always miskeyed the first time until too late.

"Neuromancer" does have a character who is neurologically crippled by their employer (with a "wartime Russian mycotoxin"). ("He'd made the classic mistake, the one he'd sworn he'd never make. He stole from his employers.")