Baconsammy
Banned
I'm looking at it in-game and it's chance of failure; you get 100% when directly in line of sight of someone, not 0%.
Manual says:
picking pockets
Interact with others during stealth to attempt to pickpocket them. The rate of successfully pickpocketing a character is determined by how aware that character and others nearby are of your character. The percentage chance of successfully stealing each item is listed next to the item.
stealing
Your character can also attempt to steal items from owned containers. As with pickpocketing, the odds of success are displayed onscreen, and are determined by how aware nearby enemies are of your character.