i suspect that steam was using a payment processor which identified that the coins were on a blacklist of sorts, and was not legitimately acquired (e.g., either stolen, or purchased with stolen money etc).
Just like the electricity cost of bank transaction cannot be easily quantified, so the problem does not exist.
Those problems only exist in Bitcoin. /s
Because it is.
Bitcoin by its very nature wants to expand to consume every possible unit of energy it can.
For example, you can't buy a gift card in an Apple Store without signing a statement promising that you're not buying the gift card because a stranger online told you to.
Sounds ineffective on the surface, especially to jaded tech-types, but it's enough to give real people in the process of being scammed an opportunity to think about what they're doing.
If someone steals 100k of cash, there is a very low probability that the serial number of those bills were recorded somewhere. And even if they were, you couldn't easily trace the money though complex systems.
Bitcoin on the other hand is a complete and open ledger. When these large heists that constantly happen, it is trivial to identify the transactions that happen afterwards.
Cash is actually anonymous and Bitcoin is only pseudo-anonymous.
If I buy you lunch today, you can pay me back next week. We're not "cash handling business[es]", so we wouldn't have to scan.
Second, I don't think it's technically possible. For companies that do business across state lines, sure, but within a state's border, interstate commerce laws don't apply. Each state would have to enact a similar law. And best of luck with that.