they were used to figure out the maximum price that people is willing to pay for each product.
Yes, but... That's okay, isn't it? Isn't it good to know what's your customer's real demand?
It depends on one's ideology.
What is clear is that it supposes an imbalance in the negotiation power between the seller and the buyer. They didn't take into account (or they don't care) that maximising their profits would lead to a 15% of families in Spain to poverty. Basic products' price like oil and milk have officially risen over 33% compared to last year, and eggs over 28% (and I think that these numbers are very conservative, as I recall buying eggs a year ago at 1.45 and now they are at 2.15). Average consumers pay these prices and it turns out profitable, but people who had difficulties to finish the month in black numbers can't scape this trap. Well, it is the same people who gave away their consumer behavioural data which is now being used against them, but up to what point is taking advantage of such ignorance ethical?
In a capitalist world, this is legal and even desirable, yes, but I can't help but ask myself whether, if we are discussing here about giving away our data (and power) to banks and governments, what is the difference with the food industry?
Sorry for the off-topic. This topic deserves his own thread, maybe in Politics & Society.