Safety of old brakes I found an old bike and I am not experienced with bikes. I am wondering if these brakes need to be changed: 



I am not sure if this is in all bikes, but the mechanism of the brakes looks too old to me. You just press the brakes and those cables get stretched and the bike stops. Is that ok/normal and safe?
Those are cantilever brakes and as long as the cables are still intact, everything works as it should and the pads still have plenty of material left, they're perfectly fine. From the photo it looks like the pads are still okay, but replacing them can never hurt. A drop of oil on the hinges might not be a bad idea, too.