it seems pointless to be arguing this point on here, but i'm a glutton for punishment so i'll give it a go. yes, intuition says that a bike without brakes is dangerous. but fixed gear bikes have a really good braking system built into them -- you can stop the bike very quickly and efficiently by controlling the speed of the rear wheel using the pedals and chain. it works exactly the same way a traditional rear brake does (slowing down/stopping the wheel), except it doesn't loose efficiency in the rain and the brakepads don't need to be replaced twice a year.
german law states that a bike must have two independent mechanical braking systems. i've put a front brake on mine, and my drivetrain is a very effective braking system, so i therefore am biking within the law.
Well within the law as it pertains to brakes maybe, and that is debatable but what about all the rest of the gubbins the German law says you need to be street legal. I would guess that you probably have about zero amount of that?
As for the brakes you reckon it is a good system but I can't see how it can be when the only way to slow down your back wheel is to pedal slower than the wheel is turning which means the only brakeing mechanism is your muscles which are no way as effecient as a decent roller brake or even the old fashioned back pedal type brakes, which also do not lose efficiency in the rain or wear the brakepads out.
I am not saying you shouldn't ride your junkheap bikes and enjoy yourself but no complaining when you end up either fined by the cops or splattered across the road when your "more efficient" brakeing system lets you down.