Your supposed to keep a safe distance to the car infront of you. If you tailgate someone, that person can slam the breaks, your gonna crash into them, and guess what? You will have to pay. If you hit a car thats infront of you, its your fault by default in the eyes of insurance companies (and in the eyes of EU law). The driver in front of you may have breaked without reason, guess what, he can break for whatever reason he likes, its YOUR responsibilty to keep a save distance to the car infront of you, not my responsibility to accelerate or let you past me in order not to get tailgated.
This is not true in the US. Intentionally causing an accident from in front of another car (slamming the brakes for no reason) is criminal here.
As I said, tailgating is just as moronic as speed-capping in the passing lane, but that doesn't make your behavior correct. Also, most speed limits in the US are legally termed "flexible" so that it's the cop's discretion:
If you're doing 76 mph in a 70 mph the cop can determine that is reasonable and safe. By the same toke on a snowy day he or she can ticket you for going 60 in a 70 since he or she can determine that speed is not safe. This is also true throughout Germany.