I think it's a skill that we all have (as INFJ's) and that we all use when we really need it, sometimes willingly and sometimes without even noticing.
As some have said before me, when I do this, I don't do it for my own benefit, but for the 'greater good' - if you want to see it like that. Whenever I see something out of place, someone being utterly wrong about something or a sittuation taking a wrong turn, this instinct activates naturally in me. I don't sit and think "right, time to start manipulating", but rather my mind see's those things that other people don't and in its willingness to help it tries to channel the 'wrongness' into 'rightness'.
The thing is that I don't have a very 'strong' presence. As neither do most INFJ's, I assume. We don't have it because we simply can't or don't want to.
I'm a moderate introvert who has a hard time speaking loudly and being assertive beyond a point. When I'm in University, with my colleagues, I normally find myself in the sideline of a group, talking about a team project or theory point which I have a strong opinion of. My colleagues will usually go on about it based on their own opinions, shouting over each other to make the strongest point, while I sit there, unable to do this. When they reach a conclusion that's wrong or shows to be inneficient, I'll try having a say, but often they're so convinced that they're right, and that the 'quiet girl who spends more time in limbo than on earth' can't possibly understand what they're talking about, that they totally skip what I said. This is, obviously, very frustrating and the reason I hate team work.
What happens then is that the part of me that knows they're utterly wrong about something, and that we're all going to fall through their stupid mistake of refusing to acknowledge what I said, kicks in with its tools. I don't have a strong presence, but I do have a very strong sense of perfection for things; I know I can do it and I can do it right. So, without even realizing, my mind works it out so that subtly, quietly, I eventually correct these attitudes and mistakes that everyone refused to realize in the first place.
And the truth is that when it comes down to it, and without praising myself here, things do come out right. I take no credit (because hilariously enough, people think they came up with the good ideas after all xD) and the project comes out sleek and smooth.
So in all, what I mean to say is that this so called 'manipulation' isn't to be followed literally as such. We don't 'manipulate' - we just try to help when the cause is right and people have made it wrong. We lack in many things, like the ability to express ourselves, to perhaps be strongly assertive, etc, so we have to make up somehow by using the greatest thing we have, which is our intuition and our need to help people and the better cause with it.
I've said.
(Gods, my posts keep getting longer and longer...)