I think it's not well known. I've mentioned the counterfeiting problem to several friends, and none of them had heard if it before. For some things, especially any sort of safety related equipment, it makes buying from Amazon a complete non-starter for me because the risk of getting a shoddy fake is literally life and death.
My experience as well. HN is one of the few places I heard people talking about the commingling problem. I wonder how Amazon is able to keep this information from being known by so few people.
