Bill Gates’ daughter’s company just got caught doing this exact same “cookie stuffing” thing. There is damning evidence, including internal slack chats and emails that have been confirmed, showing that they knew what they were doing. Something like 80% of all of their tens of millions of dollars in revenue was by hijacking people’s purchases with their affiliate code.

I expect nothing will happen to her, of course.

Don't worry about Paypal, the way any fines and penalties are calculated in the US is by estimating the total profit a company made by doing awful things and then capping the total they have to pay out when caught at 1% of that.