Burden of proof lies on the one making the claim.

>Facebook famously did an emotion manipulation experiment on 500k randomly selected users.

I don't really find that abusive or ethically troubling.

>There's a trial now alleging that Facebook used profile data to discriminate against older programmers in job postings:

Maybe this age discrimination, which was already illegal on its own, wouldn't have been possible to commit if the data didn't exist in the first place. That doesn't mean it's the tool's fault or that the tool should be illegal.

I didn’t make a claim, you did, then flipped it around and made one for me. ;)