I have always had West Highlander Whites up there on my own dangerous breed list... along with a few other more traditional, larger usually breeds. Another little white dog, the Maltese Terrier, now takes it's place on this roll, according to Australian research.
I know bites from Labradors are becoming more common - the breed that was always so steady and reliable. So why is this happening - this breed, and other little white dogs, are currently popular pets ( Maltese, Bichon Frise and Poodles are often crossed with other small dogs to create "designer breeds" ) - so are they just more commonly owned now, or is it the repeated breeding for their looks at the expense of temperament? Where do puppy mills, breeding large numbers of poorly handled/socialised puppies play a part too?
A large part of it is purely the owners failing to teach them the rules of good canine conduct. To quote some animal behaviouralists... "there are no problem dogs; only problem owners.".