If someone that has some high reputation/is your friend/etc, explicitely asks you to do something, it definitely is manipulation./quote]
I would disagree that all requests are inherently manipulative simply because they come from a friend or a person with a good reputation.
I'd say it's entirely up to you if you let yourself be manipulated from a PM. I think theymos had less than 10% success rate when he asked DT1 to exclude Lauda, which makes me believe many users don't just do anything they're asked.