Risen

This achievement is currently a bit glitched and might seem to not work. Trying to figure this out a few things became apparent; it does track the number of people you pickpocket between games, but not between different levels of targets. Say you learn Pickpocket 1, pick a few targets and then learn Pickpocket 2, going for the new options available. The game seems to differ between targets requiring level 1, 2 or 3 when counting and thus you have x amount of level 1 targets and x amount of level 2 targets. Until this is sorted, here is the easiest way to achieve this:

Start a new game and make your way to the bandit camp in the swamps. Make sure you have at least 100 gold and locate Phil who is guarding the swamp farm up the hill by the dam. Have Phil teach you Pickpocket 1. Save your game. Turn around and pick the pockets of your first target, Obel. Head down to the swamps again and find Clay sleeping by the nearest fire. Pick his pockets. Now head out into the swamps and locate Louis the drunk. Pick him too and head back to camp to find Brogar. Once he's relieved of his possessions, head up to the arena close by. Locate Brannon hiding in an alcove above the arena and pick his pockets too. That's 5 level 1 people picked. Reload your game, learn the skill from Phil and repeat this round of targets until the achievement pops.

 

Warning: You MUST let the person finish talking at every screen while picking them for it to count toward this achievement. If at any point you hit [B] to skip dialogue, it will not be counted.