Media calling "War of the hashtags". So? I don't know, it's more important who uses the hashtag, than the #hashtag itself.
You can try posting anything with the hashtag you want, nobody cares unless you have a critical and active mass of followers. If your account is rated high enough, more people will see the post and eventually reuse the hashtag.
But it's not like you post a hashtag and the world changes. It's like you hashtag what you want and almost no one gives a crap until you already have influence. That's the truth, dear mass media.
It's the war of the users with the most influence.