Today, all have become common nouns, bereft of monetary value, victims of "genericide". This term was coined by marketing mavens to denote trademarks and brand names repeatedly lower-cased in everyday parlance. Usage demoted them to the humble rank of "generic descriptor."
Scott Winokur, "The name of the game is the name," The San Francisco Examiner, February 21, 1995
The "Monopoly" case presents several difficult issues concerning "genericide" of a trademark the deterioration of a once valid, protectible trademark into a common term available for use by anyone. Of major concern is the 9th Circuit's use of a novel test emphasizing purchaser motivation to determine the genericness of the "MONOPOLY" mark. According to the 9th Circuit, the genericness of a once-established trademark depends not on any perception that the public may have concerning the jeopardized mark, but rather on what motivates a significant portion of the product's purchasers to buy the trademarked product: a desire to have the product or purchaser loyalty to a known producer. Source-loyalty motivation may be the requirement for mark validity if the 9th Circuit's motivation test becomes the standard.
Saul Lefkowitz and Barry W. Graham, "Court Rules that 'Monopoly' Has Suffered Genericide," Legal Times, March 7, 1983