If you think it's funny to speak in hashtags, like in real life, well it's not.
Also, if you think that it's proper to use hashtags to simply say things that you would have normally said without the use of a hashtag - it's not.
Jimmy Fallon and Justin Timberlake demonstrate these two rules for the social media-obsessed world in one, pretty funny video. Hat tip to Questlove for providing the only real hashtag that matters:
Image courtesy Late Night with Jimmy Fallon, YouTube