Aggressive Doberman at Tufts "Dog Park"

[josephineave.livejournal.com]

This morning at about 5:30, I was out for my early morning exercise and was greeted by a doberman running across College Ave. to say "hello" - not in the "hi-there-I-am-curious-about-you-and-would-like-to-play" manner, but in a "you-have-invaded-my-space-and-I-would-like-to-crush-your-testicles" way.  Fortunately, the dog stopped short about 2 yards from me and returned to the young woman who had taken the dog out for a walk. 

This happened right at the entrance to the Tufts "Dog Walk" area -- you know it by the sign that reads "No Dogs Allowed" (that's a subject for another day).  This is actually the second times in a couple of months that this same dog walked by the same woman has done with this. 

Other than buying new underwear or never going outside again, what should I do?  It's obvious that the two of them have some issues -- the dog isn't well trained, it's too big for her, she needs a better leash system...something.  I would hate for someone to get hurt or for the dog to get pepper sprayed, but it's really a bit terrifying for the unruly beast to come sprinting angrily toward you and I understand harsh action when that happens.  

I've never owned a dog, so I don't want to be too harsh, but there are some requirements for responsible dog ownership in densely packed urban areas.

Suggestions?  Has anyone else had issues with this pair?