Shaco boxes do a lot of damage when stacked

I just had a game with a Shaco support. What he would do is put all of his boxes into one spot and when someone accidentally ran into that area he would get a kill, mostly from the boxes alone.

Ganking became a lottery (mind you there were other things wrong with that game, doesn't change this one fact though)

We thought at first it was a bug, or cheat, it felt that ridiculous. but I checked it, did the math and they actually do that much damage.

At level 7 a level 4 box does 80+20%AP * 1,6 AS damage, Thats 128+32% AP dps. If there are three or four in one place that HURTS.

Lets say 400 dps and more, at level 7. If they don't buy Health or MR, squishies can take less than 1300 at level 7. So a Box stack can kill them 100-0 in 2-3 seconds.

A simngle box on it's own seems fine, but what do you think should they do something agaisnt stacking boxes? at least agaionst champions, he kinda needs to stack boxes in the jungle.