Originally Posted by Wikipedia

Sharking refers to a form of malicious and illegal act in which the perpetrator sneaks up on a victim, usually female, in a public area and forcefully exposes the victim's intimate parts to be seen by the public before running away. While it has similarities to the common schoolyard prank of pantsing practiced by bullies, sharking is done for the sexual stimulation of the perpetrator, and to invoke fear.

While some have categorized it as a 'prank. It is categorized as Sexual Assault or molestation in many jurisdictions around the world. Therefore punishment is more severe than simple assault, especially if there are multiple documented violations.