This is from spamming interact with target. When you use interact with target and click to move, the slave interacts by clicking on the area where the target is, or was at the time of the command. Many people build IWT into their spam key, so it's sent constantly.

If you spam it, especially while either the slave or the target is moving, you have a greater chance of "click slippage" where the click either happens in an unreachable location or acts like the mouse is being held down and moved, causing the slaves to overrun the target, hitting interact again or causes the slaves to turn around and try to re-reach the target, causing the orbiting you see.

People favor this in PvP because it makes things more chaotic for the opposing team, making the slaves harder to target and causing facing issues for the person they are attacking. In PVE, it's less used because running off ledges or into another pack of mobs sucks. Though I have used IWT spam combined with Jamba's Follow Strobing for vehicle combat like Trial of the Champion, which allowed me to launch my slaves off with Charge without losing them across the arena.