Iconoclasm is defined as the act of breaking or destroying images, especially religious ones.
For the purpose of this site, the parameters set for what constitute an "art crime" involve those acts within the confines of a museum or gallery space where a work is willfully damaged. Acts of vandalism outside these confines, may be reduced to an act of hooliganism whether or not that was the intended aim especially when they lack a raison d'être. Most of the crimes documented involve a considerable risk of retribution against the perpetrators if caught (although rarely is a sever punishment dealt) and indeed in most instances no attempt of escape is sought.
from art crimes