The Euro-step has become very popular. If done correctly (ball gathered before first step) it is a legal play. Unfortunately many players will gather ball with a foot down (now the pivot), then take their 2 Euro-steps returning the pivot to the floor: TRAVEL.
Situation 1: A1 drives to hoop, euro-steps passed stationary defender B1, A1 tripping on B1’s leg (a) within her vertical space), or (b) outside of her vertical space (e.g. feet too wide), causing A1 to fall. RULING: (a) Player Control, (b) Block.