I don't understand what people get out of that.... I've noticed sometimes people like to stand on the over look above the 1-90 bike tunnel and throw bottles down onto the path. The hubby and I went down to Lowes and bought a little broom once to put out at the end of the tunnel (after sweeping up all the broken glass), but it dissappeared in less than a day....
We even wrapped the handle in a blown inner tube that someone else had left - after running over all that glass- so that maybe people would get the idea and leave it there.