Welp, at my previous workplace, we encrypted our old HDDs, then we put them to VISE, then drilled four holes every HDDs. Then we throw them to the local electronic collection point. We did that for 10 HDDs. Yes, they were a small company. Drillin 100 HDDs is not...so wise
A site I used to frequent would take theirs out to the range and blast some holes in them. It would be effective. Wasted resources vs. data security? I guess that argument ends with which brings you greater liability. I usually just run DBAN or similar if they are still operational.
