This is an example of an unsportsmanlike foul (Criteria 3). Defenders cannot make unnecessary contact on an opponent in order to stop the progress of the offensive team in transition.
In this example, defender White 6 makes unnecessary contact with opponent Red 12 to stop the offensive transition. The defender deliberately fouls the offence to stop the transition opportunity. This is an unsportsmanlike foul (Criteria 3) on White 6.