Dogs are evil.
I've been bitten randomly while biking when some crap little dog did a run-by biting & took a chunk out of my leg for no good reason whatsoever.
Eff dogs.
Dogs are not evil, people who don't know how to properly train or don't have the time to train the dog are evil.
I have a dog and she is the best dog ever in my eyes. She listens, she does not bite. When I walk her down the street other dogs will try to get in her face barking like crazy SOB's, and what does she do? Stand there, doesn't bark back, doesn't chase. If she had a dog barking in her face wanting to rip her face off I can tell her to sit and she will.
A properly trained dog is a great thing and can be a wonderful companion. If someone doesn't want to put foward that time and effort, DONT BUY A DOG! Pitbulls etc..... they can be trained to be wonderful dogs also, but it takes a little bit of effort by their owner.