Originally Posted by BassNotBass

Not only is it against the law on many roads (as you pointed out) but it's also unsafe. The closing speeds going head on into traffic is greater so there's less time for anyone to react to a potentially bad situation and the greater speed differential can hurt a lot more (cyclist doing 20mph and a car doing 30mph is the difference of 50mph (head on) vs 10 mph (rear ended)). If a rider wants to be aware of traffic coming from behind, they should use mirrors... that's what they're for.

I come across a lot of salmon on my rides and they think they are being safer but then they don't seem too bright to begin with... Darwinism in action.