Complex sentence: Gallon smashing gained popularity in 2013, following a series of videos posted on YouTube by three teenagers from Vienna, Virginia, which were viewed more than three million times before being removed from the site.
Split into simpler sentences: Gallon smashing gained popularity in 2013, following a series of videos posted on YouTube by three teenagers from Vienna, Virginia. The videos, known as "Gallon Smash", were viewed more than three million times before being removed from the site.