Just because you have a service dog doesn't mean you can do whatever you want with the dog.
There are expectations, and regulations, that service dog handlers must comply with.
Shooting someone because you don't want to do what the ADA says you must is just plain stupid.
Now, I'm not going to discuss the article I linked to in any depth or detail because I wasn't there, what's written in the article is all I know, and I am half a continent away - I will probably never know the details.
However, since I've frequently discussed the rights of disabled people to have and to self-train service dogs, I think it's only fair to discuss the responsibilities that accompany the rights of having a service dog.
First, to help you understand what I'll be saying, a brief glossary of terms:
Handler - the disabled person teamed with the service dog/horseNow, onward!
Team - a service dog and a disabled human working together
Service Dog - Almost always a dog, due to the latest changes in the ADA laws and regulations, however, Seeing Eye Ponies are also accorded the same access rights as seeing eye dogs. No other animal, even though it assists with a disability, has the access rights of dogs and seeing eye ponies. For brevity, service dogs and ponies will be simply called "service dogs".
Assistance Animal - all other animals that assist disabled people - they do not legally have the access rights of service dogs in stores and restaurants and hotels, although business owners may extend that right to them. They do have housing rights to live with their owner/handlers in rental properties that otherwise forbid pets.
Challenge(d) - When a business owner/employee asks if the dog is a service dog. Many business owners are unaware of their rights as business owners - or assume they have rights they don't have. Some are polite in asking and some are rather belligerent. Most fall somewhere in between.
Disabled people that can be helped with the services of a service dog have the right to be accompanied by that dog in grocery stores, restaurants, hotels, airplanes, beauty salons, boutiques, and other public areas - basically, anywhere the disabled person can go, their service dog can go. Business owners have the right (and the obligation, I'd say) to ask the disabled person: "Is that a service dog?" and "What task does it perform for you?" They DO NOT have the right to say, "You can't have pets in here." or "We don't allow pets." or "What's your disability/handicap?"
Disabled people have the right to self train a service dog for their needs since the wait list and availability of service dogs is lengthy and often expensive - many disabled people are also poor and can't afford a service dog. The only way they can get one is to train one themselves.
That training must include the following:
1. The dog must be spayed or neutered before training begins. This prevents the dog from being distracted by the canine heat cycle, as either male or female. An intact male or female dog is not a good candidate as a service dog.
2. The dog must be socialized. Earning the Canine Good Citizen certificate is a good first step. Aggressive dogs, dogs who bark at other people or dogs, who chase other dogs (or cats or birds or squirrels), who eat dropped food in public areas, who take food off of tables or beg for food, are not good candidates as service dogs and must be trained out of those habits or a different dog chosen.
3. Although special vests, leashes and harnesses, patches, badges, and other accessories are not mandated - and no business owner can require them on service dogs - service dogs must be kept within 3 feet of the handler, and must be leashed (an ordinary leash works just fine) or otherwise under the control of the handler. There are exceptions made for dogs who pull wheelchairs, and dogs who are trained to retrieve items for the disabled as they need to be able to go beyond the 3 foot limit.
4. Business owners and their employees have the right to ask that the dog be leashed when not performing its tasks. This is for multiple reasons - one, it makes sure the dog is within the prescribed by ADA 3' limit, it keeps the dog under the control of the handler, it may save the life of the dog if attacked by a pet dog, and it reduces complaints from other customers. Oh, you'll still get the complaints, but if you're complying with the ADA regulations, those complaints are easier refuted and dismissed. As the service dog handler, you must comply with the business owner's request to leash your service dog, or prove that you can control the dog through voice commands or signals. The business owner also has the right to request that your service dog be kept within that 3' range except when it is performing an actual task that takes it outside that range.
Itzl is generally in a carry pouch because of his small size. His trainer and I decided that was the best way for him to do his job since when he was on a leash on the ground, he was often too busy dodging people's feet to do his tasks.
5. Service dogs need annual or every other year re-evaluation and up-training. Re-testing for the Canine Good Citizen certificate makes sure the dog hasn't developed any lazy or bad habits. Up-training makes sure the dog continues to meet the handler's needs.
6. Service dogs need bi-annual vet exams. Yes, they are expensive. Service dogs need all their vaccinations - including the flu shot! - because they are exposed to many more diseases out in public. They need frequent parasite check-ups because of that extra exposure, too. Your service dog needs to be in optimal health to help you. There is insurance to help with the costs, and some vets now have pre-pay plans where you pay a small amount each month into an account and then use those funds for the vet visits. Itzl and Xoco each have such an account to pay for the things their insurance doesn't pay for.
7. Service dogs need regular (and frequent) grooming. They need their nails kept trimmed and their paws tended because they use them more than pet dogs do - and in rougher places. Dog shoes can be essential, so be sure if you use them that you get ones that are suitable, not necessarily "cute". Frequent bathing reduces dander and helps when out in public among strangers who may have dander allergies. It also reduces that "doggy" smell some people find objectionable and helps you find and prevent parasitic infestations like fleas and ticks.
8. Although this isn't stated anywhere, handlers should not become aggressive when challenged no matter how rude or provoking the challenger is. It can be really hard not to become aggressive right back when you are being physically pushed through the door, but getting angry and fighting back at that moment is not going to help anyone, least of all yourself and your service dog. Have your attorney on speed dial. I text mine, and take photos of the manhandling and rough treatment - as well of the store's name. My attorney often calls them within minutes and follows up with a letter. If I ever go back, I am often treated much better. So far, it has never led to an actual court case, most stores realize they are in the wrong quickly, and I'm always willing to educate them about handling the presence of a service dog (usually, just treat the human as they would any other customer and ignore the dog entirely).
Some stores are very good at handling the presence of a service dog (Hancock's, Michael's, Steak and Shake, Sears, Dillard's, Walgreen's...), and some are rather belligerent. WalMart is one of the rudest and least service dog friendly places I've ever been, so I stopped shopping at WalMart 7 years ago. JoAnn's Fabrics is right behind them in my personal experience. Target is inconsistent - sometimes they follow us (and Itzl always gives me the "We've been made" signal when a security officer or store detective shadows us when we shop, so I know they are there, but after that, we tend to ignore them unless they confront us), sometimes every single employee has to stop and us and point out "Pets aren't allowed, you'd better leave", and sometimes, they simply wave and smile as we shop. I never know what treatment I will receive in a Target.
In the end, it's best to just leave the store and let the attorney handle it. They love this sort of stuff, and if you have documentation (photos, names, addresses, witness contact information), so much the better!
9. The business owner has the right to expel your service dog if the dog is being disruptive and can't be brought under control. and as the handler of the service dog, you must comply by getting the dog under control and quiet (if it is barking) or remove the dog from the business. The most common reason for expelling a service dog is barking. Most service dogs don't bark in the course of their duties, and the ones that must bark don't do so in an uncontrolled manner. A barking dog is considered a disruption and the ADA allows business owners to request that the dog be removed under those circumstances. Comply graciously and the next time you shop there, with a better-behaved service dog!, you'll both be welcomed back.
Other people having hysterics or fits over the dog's presence is not grounds for expelling the service dog if the dog is otherwise behaving appropriately. Other people complaining about the presence of the service dog is not grounds for expelling the service dog. Other people claiming an allergy is not grounds to expel the service dog. (Allergies are either dander or saliva related -both are proximity dependent so they just need to keep their distance).