There's one thing a bit off the topic of technology, security or trading, but is in way related. I travel a lot and use hotel and airline loyalty schemes. I rarely claim the awards from the schemes but instead I prefer to allow the points to build up to maybe use for a big trip. As it happens I don't go out of my way to use those airlines or hotels. I travel mostly out of necessity to support my business. What really gets my goat (UK english colloq. "annoys me") is that once the points have been awarded the airline/hotel think they can snatch back the points if I don't use them within a given time frame. So far as I'm concerned that is theft by the supplier, I don't care what legalese grey fine print is tucked away in some obscure place. It is theft, plain and simple.
So when a supplier such as British Airways (BA) of the Hilton Hotels group (Hilton HHonors™ scheme) claws back points from me I always punish them by withdrawing business from them. The punishment always costs them more that the value of the "points" that they've stolen from me, and the business goes to a competitor.
Another extremely annoying business practice is selling my account to another business as though my business with the supplier is some kind of commodity they can package up and sell to another business. The banks and credit card companies are particularly prone to do this. When I do business with another business it is because I choose to do so. Once again I punish the business who "bought" me for assuming that I'll do business with them. Sorry guys but you have to earn my trust, you have wasted whatever you paid for me and it will go to your competitor. British Airways have played a similar game by selling my customer points holding to Avios, sorry guys it doesn't wash, you both lose.
If big business had the courtesy to ask me if I had any objections about being transferred to another supplier I might be more amenable, but they don't so they lose. Loyalty is a two way street.