There’s a fellow who years ago filed a trademark application for “listserv”. It registered, and by now he has filed three renewals including an incontestability statement. You can see the TSDR record here. The term has long since become generic.
The registrant’s web site uses the term as a noun, as you can see in this screen shot.
My firm sponsors many listservs, some of which are listed here.
So, are going to petition to cancel LISTSERV?
Nah, that costs money. Hopefully the guy will eventually figure out that it’s not worth spending money to keep renewing it.