I do agree that any rabid dog would probably act like that. However, aggressive breeds are more dangerous and should be watched more carefully than the non-agressive breeds. If you go by popularity, then Labs should be at the top of the list of dogs most likely to kill. If a dog has a history of biting, and is an aggressive breed, then they should probably be put down. I have known some people with Doberman's, and these dogs were very nice. However, take a look at the below link. This mauling occured yesterday, I believe.
http://www.kyw1060.com/news_story_detail.cfm?newsitemid=31935 Looks like age doesn't necessarily bring wisdom. I would NEVER adopt a full grown dog of an agressive breed.