Most likely to end
badly

Cinnamon Challenge

Most popular: 2007-2012 YouTube uploads: about 200,000

The cinnamon challenge involves ingesting a spoonful of cinnamon in one minute without a drink. It gained momentum when videos of the challenge started being posted to YouTube. For the people watching the event, it can be very funny, but the challenge itself poses serious health risks including vomiting, choking, and even collapsed lungs, pneumonia, and possibly death.