Many once famous marks have become generic through public misuse and the failure of trademark holders to counteract that misuse. Escalator was once a trademark but fell into the generic abyss because its owner failed to protect the mark. Kimberly-Clark, the owner of the Kleenex trademark frequently advertises the fact that Kleenex is a trademark and not a generic term to prevent the mark from becoming generic. Nabisco does the same with Oreo, and many corporate trademark owners follow suit. The risk that one's famous mark will become generic through public misuse is one reason that famous mark holders are sensitive about the unauthorized use of their brand names.
Famous mark are especially vulnerable to such abuse.
I'll pass along any information that's forthcoming.