X updates terms, countersues to lay claim to the 'Twitter' trademark
techcrunch.com
techcrunch.com
If you drop something valuable in a legal domain where after 3 months it's finders keepers it doesn't magically become yours again because you said "not like that" basically.
OTOH if there is no legal domain with an N month rule, you can say "thats mine" forever.
"we didn't mean to let thermos become a generic" wasn't really a workable argument.
(NAL. probably using words in ways which make Lawyers wince)