As far as I'm aware, there's a fine line between layoffs or reductions in force and firing for poor performance. Its legal to cut an entire division, or to cut some percentage of a division's head count and come up with some way of distributing it across the org. It is not legal to find your worst performers, fire them all at once, and call it a layoff.

Happy to be wrong here though, just trying to be clear with the line as I understand it. Someone coming by may know for sure.