Vandalism
Vandalism is a crime that is done by destroying or damaging the property of someone else. This can include graffiti and website damage.
A person that does this is called a vandal. The name comes from the Vandals, a tribe that attacked and damaged the city of Rome in 455 CE.
Examples
Examples of physical vandalism include salting lawns, cutting trees without permission, egg throwing, breaking windows, burning things down, spraying paint on others' properties, and tagging.
Internet
Many websites, such as wikis, such as Wikipedia, forums, and blogs, can be changed by anyone. Because of this, they can be "vandalized" by adding comments or replacing everything on the page with spam, nonsense or other silly content. It is a kind of trolling, and some of these websites have special users, called administrators, whose job is to remove the vandalism and to block users who do not stop vandalising.
Vandalism Media
The Vandals sacking Rome in 455 AD, painted by Karl Bryullov c. 1830
Armand Călinescu's memorial with the bronze plaque stolen and the name of the assassin written over
Headless statue in Ely Cathedral; ideological vandalism during the English Reformation
Two billboards with the same original content, the billboard on the right being an example of subvertising—vandalizing with a political message
A website defaced by the Lapsus$ hacker group
A sticker reading "the HELL with SHELL" photographed in Michigan in 1973
Traffic signal light vandalism portraying cannabis in Bogotá, Colombia
Vandalized ladder stand in Germany
Vandalized seat inside a passenger car on a train in the Czech Republic
A broken shopping cart, thrown into a waterway, Netherlands