Amazon Prime: Faced criticism for insensitive tweets during Prime Day.

Cinnabon: Tweeted an image of Carrie Fisher with a Cinnabon hairdo after her death, which was seen as insensitive.

Celeb Boutique: Used the Aurora shooting hashtag to promote a dress.

Epicurious: Promoted recipes using the Boston Marathon bombing hashtag.

DiGiorno: Used #WhyIStayed inappropriately, missing its association with domestic violence.

Kenneth Cole: Tweeted about the Arab Spring to promote a sale.

McDonald's: #McDStories campaign backfired when people shared negative experiences.

RIM (BlackBerry): #BeBold campaign was mocked for its outdated image.

JP Morgan: #AskJPM Twitter Q&A backfired with users criticizing the bank.

British Gas: #AskBG session during a price hike led to angry tweets.