Need to have some Idea's.

I bought a progress 25mm bar, been on the car for a about 9 months. I recenlty started hearing some squeaking noises...

I look under the car, only to find this....



Why would this happened, I installed it at ride hight. My car isnt lowered, could it be the metal is too thin? This happened on my other sentra as well. Also installed at ride height. I removed the bar today, and I will look for some beefier brackets.. if they exist.