[mdex]

There's the overall creepiness of hordes of data containing your entire online history being used for the sole purpose of predicting what you'll buy and manipulating you into buying it.

But I think there's more to it than that:

It's customary in trade to not have hidden costs or unintended consequences of using your product, anything otherwise is dishonest. And insisting a product is "free" while having hidden schemes to extract value from customers is scam-y.

Then to say ad-hoc that its a "fair compromise"... but if it was a "good deal" why not be upfront about it, why try to hide it? "You should've read the EULA." Well, a bet a bunch of people being targeted/tracked by Google & Facebook are children, many too young to consent, some maybe even too young to even read...