I totally agree that any dog can be scary. That said, if attacked at my home I'll simply turn the garden hose on them. 99% of the time water from a garden hose will make them turn tail and run.

My dog has run out the front door of the house twice. Fortunately, both times I got him back. I'm now super super careful. I now have a pet gate that separates one part of the house from the garage door area. I then go out the garage door instead of using the front door to the house.

Dogs can be fun, however their owners still need to watch them closely and for god's sake, keep them leashed when out for a walk.