You never know, sometimes they actually find these thugs. Hope so!
Because I grew up in the Detroit area and my father was from what was basically a ghetto, my father taught us Basic Street Smarts at a very young age. And those rules still hold true today. I don't imagine that Stockholm is anything that extreme, but thugs use the same process wherever they are, all over the world. Pickpockets use the same tricks all over the planet.
For instance, if somebody asks you for "change" -- they don't REALLY want change, they want you to pull out your wallet so they can steal it, without having to hit you on the head and experience the inconvenience of having to search for your wallet. Same thing with the phone: it's easier for them to make up some story to get you to pull out your phone, so they can steal your phone without having to LOOK for it. The rest of what happened to you is just to scare you, partly because that's part of their job as a thug and partly because they're probably sociopaths (probably partly the reason why they have "Thug" on their resume).
Suburbanites here in Chicago make it much easier on phone-stealing thugs because the suburbanites have their iPhones in their hands on the L or on buses all the time (and then are "SHOCKED" when a thug so easily steals it from the suburbanite's grip at a stop, the thug then disappearing out of the train and into the mass of humanity in a big city).
The other main rule of streets smarts is to be aware of your surroundings at all times (hence, no iPods, iPhones, daydreaming, etc.) Thugs choose their victims based on how distracted people are; distracted people, daydreaming people, etc., are easier targets.
So, it's far less likely that this will happen to you again because, unfortunately, you just acquired some street smarts. Without being seriously injured, thank God.