Accountability in a Scrum World

One day last week, I was reflecting on the day I had, which included a Sprint retrospective of a failed Sprint - the second consecutive failed Sprint. This got me thinking about accountability. Specifically in the terms of Scrum methodology. In a Scrum team of peers from different disciplines (and different managers), such as PM, Dev and Test, how is the team held accountable for their results?

If a team fails to comlete their Sprint goal, what is the concequence, or is their no concequence? When it comes time to review the performance of the individuals, how do you rate them against the success and failures of the team. Does a developer, who completed all her tasks in the Sprint, get penalized for the failure of the Sprint?

Imaging a Scrum tean that has failed two consecutive Sprints. Their Sprint goal for Sprint 3 is "to accomplish the Sprint 1 and 2 goals." There was (and is) no concequence for the previous failures. What happens if Sprint3 fails?

Ultimately, following the Agile guidelines, if the team fails, all of the individual contributors have failed. There is no such thing as individual success with a team failure.

So, how do we hold a Scrum team accountable? What concequence is there for failure? We frequently reward project teams with successes (even late successes) through ship parties, recognition emails, awards, extra days off, etc. There is nothing driving the team to prevent failure beyond their own pride. Is that enough?