In the successful cases it is easy for the demand to recognize what they are getting. Employer just has to demand passport and they can avoid hiring illegals. Just looking at the person is enough. Same with child porn. Same with anything else where we have curbed demand side.

How would you say Microsoft is able to recognize where the cobalt came from?

I can’t really see any way here that would not be a de facto ban for the whole material.

The same way we do it with other resources of this type. And yes, we do this with other resources. Oil & gas, medical marijuana, diamonds, et al.

This is a solved problem. What you and other people are arguing is that it's not solved perfectly.

I don't really give a shit if it's solved perfectly. If we go from say 66% of cobalt being bloody down to 33% of cobalt being bloody. That's a win. We can, over time, learn and adjust to bring it down even further.

Perfect is the enemy of good.

Plus in most cases they are not using it directly themselves. They are several hops away in the chain, using a part that may contain the wrong type of cobalt.