I mentioned overbooking last year.
A lot is being mentioned about how what United did was legal.
A few are talking about it being wrong.
You might notice that legal isn't the same as morally right. There's lots of perfectly legal acts which are morally wrong.
There's lots of immoral people who work hard to insure that many of those acts of wrong remain legal.
I take the position that it's morally and ethically wrong to sell something you do not have to sell.
If a plane holds 100 people, then you can only sell 100 seats for a trip. The ethical position is someone has paid for that seat and it's theirs to use or not.
Writing a contract so that you don't have to honor a sale even if you're in the wrong is, well, wrong. But it's legal.
I've long avoided, where I can, contracts where all of the obligation is mine. This is why I don't have credit cards and very rarely fly.
There's some inconvenience associated with this, but for the most part it's minor.