The NYU's investigation of Facebook ads has its participants use a browser add-on that incidentally reports other people's personal data when it appears on the participant's screen. Arguably, Facebook is legally bound to try to stop its use.

Facebook may not have the legal power to stop it, and we must hope it does not get that power, because this research is vitally important. Unless, that is, new laws compel Facebook to hand over its preference algorithm (in every version) for investigation.

The experimenters are morally bound to inform participants that the browser add-on will show the experimenters other Facebook useds' personal information they Facebook shows them. That raises another legal/moral question: is it legal, and is it moral, for a participant X to knowingly hand over per Facebook "friends"' data to the experimenters?

IANAL, but I think it is legal, because X has no obligation of secrecy to per Facebook friends. I think it is moral, provided X informs all per Facebook friends that perse will do this, and gives them a chance to avoid showing their data to X.

However, if they are wise, they will be more hesitant to show their data to Facebook than to show it to X and the experimenters. Which means they should stop being zuckers — stop being used by Facebook.