That thingy is an airsoft gun that shoots 6mm plastic pellets and they are useful toys.

Pretty much the Asian answer to paintball. Its huge over there and in Europe and pretty strong here in the states. Some of the higher end guns are useful for training purposes in terms of practicing draw because most are the same dimensions as the real versions. Some are full metal and last I knew there was even a norinco subsidiary producing steel versions of AK airsoft guns that is identical in weight, controls, even down to the wood. There are versions that actually eject fake shells! A few organizations even use airsoft PTWs for tactical training in place of simunition and MILES systems. That little one is great for kids, but the adult versions can launch a dozen pellets or more a second at (usually) 250-350 FPS with some versions and modified versions capable of 400-500+ FPS. And yes, they are used to shoot at people with proper clothing and protection and rules like "MED" minimum engagement distance...cause a 6mm pellet can penetrate skin layers when too close. Faster rate of fire, velocity and range over paintball.