For me it is when companies/services market themselves as donating to XYZ cause if I buy their product. If they want to donate, they should have already done that with the money they have. Asking me to give them profit so that they can donate is so obviously pretentious.
I had to order something from aliexpress, because I couldn’t find it anywhere else (except even worse chinese websites). I got mails for months, literally. I would block that adress and they’d just send me mail from a different random generated adress. They’re the worst. I don’t even want to know what they’re doing with my data.