Recently, I found out almost the hard way, why it’s absolutely necessary to ground those 3/2 plug adapters. My “new” house is a really old house. read: circa 1835. 90% of the outlets in the house are only 2 pronged. This meant, if I wanted to use any of my nifty modern technology I needed an adapter. You’ve seen them, usually grey, squarish, metal loop at the bottom near the 3rd prong.
Anyway, around Christmas, we’d taken the family to my parents house in NH. when we got back, my PC was off. (meant we lost power sometime over the weekend.) Well, good a time as any to redo the plugs. Huz had asked me if I’d “grounded the plug” before we left.. I was like “what are you talking about?” I seriously didn’t know to do that. SO he was going to screw the grounding ‘wire’ into the outlet screw . However, when he unplugged it from the wall, it was still attached to the power strip plug. he had to pull quite a bit to get it to detach.
We were VERY VERY lucky. The plug was burnt and melted. when attempted to re-use, it arced and sparked and that was it..into the trash it went. The next day we went to the hardware store and bought a handful of new ones, and made sure to screw them into every outlet we’re using them on.

When using them for a temporary purpose, say, for a couple of hours, it’s most likely harmless. However, in a more permanent situation, such as home office equipment, well, grounding it, is ALWAYS the way to go. Get out your screwdriver, take out the screw from the face plate, plug in the adapter, put the screw back in, going through the grounding wire, and voila! it’s all safe to use!

for your viewing pleasure, the reason why you need to ground your 3/2 adapters ALWAYS!

Someone was definitely watching over us.