STOCKHOLM -- Maybe it was abstract impressionism.

Passengers in Stockholm were terrified when a masked man spray-painted graffiti inside a train, then smashed a window and threw himself onto the platform.

Officials were flabbergasted to learn the rampage was part of an art thesis. And they didn't seem to appreciate the artistic merit.

Chairman Christer Wennerholm said the transit authority filed a complaint against the student Monday, demanding 100,000 kronor ($12,000) in damages.

The unidentified student included video of the vandalism in his thesis at the University College of Arts, Crafts and Design. The school said it doesn't allow students to break the law, but added it wasn't clear whether the student participated in the vandalism or merely recorded it.