I've somewhat recently witnessed, in a few different ways, some pretty drastic misunderstandings, as well as some genuine anger and hurt over one simple thing: communication.
I am both an offender and a victim in this unfortunate trend: the trend of being passive aggressive, not saying how you feel or what you mean, protecting oneself from being hurt at the expense of others, and simply refusing to be straightforward in conversation.
It has affected everything in my life, from something as stupid as an online game to something as serious as my relationships with the people I love. The amount of misunderstanding and assumptions that are made out of fear are simply unbelievable. What is even more disturbing is that when we act out of fear, we are being selfish.
If you can acknowledge that and are okay with it, fair enough. However, the selfish person suffers from many setbacks in social situations. By necessity, they are not treated with the respect that a considerate and straightforward person would be, because in general it comes down to being inconsiderate and even rude to them because they will not be honest about their feelings, or to playing a guessing game, which leads to more assumptions and more misunderstanding, especially when it all goes unsaid.
It is amazing the lengths that a scared person will go to to avoid confrontation, or rejection, or even addressing difficult things that will end positively if they would just be said. Manipulation is not to be opposed because of some kind of metaphysical wickedness, it's a problem because it creates distance between people, it makes drastic violations of others' personal freedom, worth, and lives possible. It is hurting other people, and in general, it tends to be harmful to oneself. The more people you manipulate, the fewer genuine connections you will have, and that is sad.
Manipulation, even for the purpose of a positive ideal, is still a fundamental disrespect for the person you are manipulating, and it is still a dehumanizing force that affects you as much as the person you manipulate. It is for this reason that you can have all of the best intentions in the world and still create severe problems with your actions, with your words, and with your intentions in situations.
To digress to the original point, I think it's helpful to say what you mean, even when you feel you're risking something of yourself or when you fear the retaliation of the person you are speaking with. Of course, this can not happen all the time, however, as much as is possible is beneficial to both oneself and to others in the situation.