If someone is spreading rumors, then it's also people that have those particular dogs. They're the ones telling me and my coworkers what happens.
There are bait dogs. I've seen them myself, and it's terrible. I've had people brag about how they feed them gunpowder to make them angry. I don't know if it's true that it works that way, just that people have told me they've done it. I've seen more ways to be cruel to animals than I care to think about. It's one of the worst parts of my job. After all that I've seen over the years, I truly believe PEOPLE can be evil. I have no doubt of that. But dogs are a product of their breeding, training and treatment. And while no breed is better or worse than any other, I have seen certain breeds be the target of a minority of people who use those dogs to create an overly aggressive animal.
Like I said, I greatly and sincerely appreciate your placing the blame squarely on the owners. I'd simply like you to acknowledge that it's untrue that the majority of dogos are kept by bad guys, for one thing (or that "the type of people who tend to want these dogs" are bad people), and that any number of molossoid or guardian breeds are far more likely to be human aggressive by nature than a pack-hunting hog dog. If you are not yet seeing mastinos or cao filas in crackhead back yards, it's not because dogos are the bestest badass dog out there, by far.
I truly do appreciate the way in which you're approaching this; I am simply troubled by the emphasis on my breed as having characteristics that make it more dangerous than any other breed when mishandled. Any breed can be trained to be aggressive. I have a great deal of experience and many, many years in this breed and despite your few encounters with chained and abused dogs, can assure you that their character is, on the whole, exactly as described in the standard: "cheerful, frank, humble, friendly".