A lot of people link all there accounts and will post the same content on all outlets. There is actually an option for it. Hashtags have outgrown just instagram or twitter. Even if they can't accomplish anything. I see a lot of ignorant folks who text with them to add subtle emotion.
For example someone could text me " i just shot a damn 96 today. #golfishard". While ultimately the hashtag is irrelevant (and douchey), it still adds some substance to the text.