[cheesemaster]

If the 9 justices don’t know the law, how is the average policeman going to know more than a fraction of the laws he or she is expected to enforce?

Ignorance of the law not being an excuse should clearly cut both ways. Apparently, it does not. I'm surprised by Thomas.

[Gaffer]

I’m not. Had the Supreme Court not been privy to the actual drugs, etc. in this case, but rather something innocuous, they’d have likely ruled differently.

They stretched their conclusion based on the ensuing crime rather than the one (misinterpreted infraction) which begat the finding.