"It's easier to ask for forgiveness than permission" is a very popular mantra among the boy wonders of Silicon Valley.

Was the mantra of Grace Hopper, who I wouldn't necessarily describe as a 'Boy Wonder', however she used it in the context of 'borrowing' equipment and machine time from bits of the navy and academia.

She was being dry witted about tatting stuff, not recommending human testing.

When does any company get consent for changing its product or advertising and measuring the response?

I never gave my consent to McDonald's for putting up a billboard or changing their menu or their recipe.

This is a very good point in its own right (though not a point for or against fb doing this per se). Not sure why it appears in grey.