It’s impossible for a dog trainer to go to a function and not get asked questions as soon as people discover what you do for a living.
As expected, this occurred at a function I was at not long ago.
A couple was telling me about their experience with a trainer. They had been having challenges and needed help. They took their dog to a recommended trainer.
They proceeded to describe to me how the trainer (I use this word loosely) took the leash, lifted the dog off the ground and helicoptered it.
That is horrifying enough to listen to. What really upset me was the manner in which the story was told. With some laughter, smiles and an overall sense of amusement.
“The dog never did that again”.
I said to them there is nothing funny about what they watched. 
It was abuse. It was horrifying.

The sad part for me, in addition to feeling awful for what this poor dog experienced, was the overall attitude that it was somehow okay to do this.
It is never okay to string up any animal in the name of “training”.

I will never stand by while someone laughs at the abuse of an animal. I will call you out on it. I will also try to educate you.

The dog training industry, at this time, is unregulated. There is no universal standard or code of ethics. We are trying to change but it's a slow process.

Ask questions. Ask specific questions. Ask until you are 100% convinced the person you are entrusting your beloved pet to, faults and all, has a solid understanding of the science of learning and can tell you how they acquired their body of knowledge.

You wouldn’t go to a Dr. if they told you their education came from watching a lot of medical dramas like Grey’s Anatomy.

Abusing animals is not funny. Inflicting pain and fear to stop unwanted behaviour is inhumane.
There is no reason for it.