Hmm. Maybe you were thinking about elemental mercury vs methyl mercury? That’s a case where the danger (at least through ingestion) depends greatly on the format.

It’s because of the ability to trade items with other players. Any exploit that affected item drops or crafting creates the potential to upend the entire global market in the game, affecting the experience of many other players who might play mostly alone but will often look to the market to trade for items they need.

I didn’t know they’d be able to tap into the Firefox profiling tools, that’s neat! Probably great data to have as they get into debugging of more complex websites.