What failure examples of ICO token sale do you know?

It's really interesting to see such a Hype on ICO market. But I think it would be really interesting for the community to discuss failure examples of token sale. When the goal wasn't achieved. What mistakes did happen during ICO preparation of such a project?

Please write your opinion in the comments. It's interesting for me, as we (as all other people on the planet right now, i think Smiley ) are going to make our own ICO soon, so we are in process of exploring this question.