Add Yahoo as a preferred source to see more of our stories on Google. The Federal Bureau of Investigation headquarters are pictured in February in Washington, D.C. On Wednesday, the FBI's uniform ...

*It starts with a single post. A location. A time. A challenge. Within hours, hundreds of teenagers descend on a city street, ...

Every once in a while, crowded train stations have been known to break into song and dance and then disperse as if nothing happened. Large groups of people freeze for a period of time and then ...

The 2010s saw a peak in popularity for the art of the flash mob. People were seriously obsessed. But after a while, many took on the view that if you’ve seen one, you’ve basically seen them all. Well, ...