theory - Swiped vs. Sniped

While both words are used to describe the taking of objects, there is a great difference in the context they may be used in. Swiped always refers to a horizontal hand motion similar to a magician's slight of hand. Sniped refers to a more stealthy maneuver requiring the element of surprise, and is deserving of the exclamation "Face!"

If you take a pencil off the table, it is swiped, where as if you take a pencil out of someone's hand when they are looking the other way, it is sniped. 

It's science.