A story in The Register discusses an infrastructure compromise in Poland orchestrated by a motivated teenager:

Transport command and control systems are commonly designed by engineers with little exposure or knowledge about security using commodity electronics and a little native wit. The apparent ease with which Lodz’s tram network was hacked, even by these low standards, is still a bit of an eye opener.

Problems with the signalling system on Lodz’s tram network became apparent on Tuesday when a driver attempting to steer his vehicle to the right was involuntarily taken to the left. As a result the rear wagon of the train jumped the rails and collided with another passing tram. Transport staff immediately suspected outside interference.

The youth, described by his teachers as an electronics buff and exemplary student, faces charges at a special juvenile court of endangering public safety.

A “little native wit”? It actually does not sound like there was much ease, since the teen reportedly spent a great deal of time studying the system. I guess what I am saying is lets give this guy some credit. He did not just park his car on the tracks, he actually did some research and development.