Will an e-collar or correction, hurt my dog or make my dog fearful. Are e-collars cruel?

Teaching a dog how to learn. Clicker training. marker training. Balanced dog training.
This lovely young dog does a beautiful job of helping to dispel the MYTH, that appropriate guidance and ( where necessary ) correction through the use of an e-collar for inappropriate behaviour choices, retards learning potential and causes dog to fear experimentation.
POOR - EXCESSIVE - NON-CONTINGENT correction will do that for you .... I prefer to simply install boundaries of acceptability - To highlight the lines between black and white, to reduce clarity of requirements to their simplest level of understanding - Namely that certain things result in favourable outcomes, whereas certain other things result in unfavourable outcomes.
For the vast majority of dog owners, this is all they and their dogs require - Nothing more.
Far too many people are claiming themselves to be 'professional dog trainers', yet their primary motivation is not the animal before them, the current issues facing that animal and the requirements of the owner. Instead, these self-proclaimed 'modern dog trainers', who supposedly use 'science based dog training methods' or 'reward based dog training only', are in many instances ( though obviously not all ) doing genuine people a great disservice. This disservice stems from a dishonesty, a dishonesty involving either deliberate untruths, unsubstantiated claims or emotive rhetoric. FULL facts are either wilfully or ignorantly distorted or omitted, leaving frustrated, desperate or guilt ridden owners feeling at a loss as to how to rectify the issues they are facing.
It is wrong - and any and every level, the promulgation of factually inaccurate or fabricated, selective science is wrong.
Many of the dog training videos I record and share, are designed not so much to showcase my own dog training or problem behaviour modification abilities ( or lack thereof, depending on the extent of your bias and cognitive dissonance ) - But rather to show FIRST HAND, the true and honest effects of a holistic approach to training dogs and addressing problem behaviours.
jamie penrith FdSc Canine studies
Take The Lead Dog Training - Professional dog training and residential board and train / boot camp dog training throughout the UK
Professional UK dog training
E-collar professional
Expert e-collar advisor
Canine behaviour modification expert UK
Applied canine psychology UK
Expert public speaker regarding applied behaviour modification
How to raise the perfect puppy
How to prevent behaviour problems in your dog before the start