I agree! I'd put unethical behavior like distortion and lying in a different category than Facebook's, but I agree. I was trying to kill the parallel between Facebook intentionally manipulating user emotions for science, and Budweiser intentionally manipulating viewer emotions for beer sales. Video games work here too: Amnesia scares the unmentionables out of me, but I'm ok with that, because I know that's the whole point.
Another missing component here is user control. I can turn off the commercial and stop playing the game. I'm currently working (in a minor capacity) on the National Children's Study, and our participants can walk away at any time. When the Facebook subjects on the negative side started feeling slightly more sad, they had no idea why, and no clue how to stop it.