Increasing automobile safety concerns around the world are leading to new airbag rules and improved crash safety standards. Now, German rental company Sixt is moving safety forward in a different manner: by removing all Porsches from its lineup.

Citing numerous high-speed accidents sustained by less-than-experienced customers, Sixt believes the responsibility of driving such a powerful car is simply beyond the car-renting public. In a recent example of such automotive hooliganism, an unnamed customer took one of Sixt's Porsches to the Nurburgring and burned so much rubber that all four tires required replacement.

Having seen the way most people treat rental cars, we're surprised Sixt could even consider purchasing a fleet of Porsches. They're not called "speed bump testers" for nothing.