Of course we have the responsibility there.
But internet, and social media, is unlike any other communication medium we used before.
I can't remember now where I have read this, but the topic was how adjustments to Facebook news feed (wall) algorithm allows to "adjust" level of happiness of the end users. You could say that television could do that as well, and to an extent it does, but not with the surgical precision of Facebook. And, with a very different understanding/perception of the users. We do hold this image of internet being a "many-to-many" dynamic, as opposed to "one-to-many" which would have been the old mass-media structure. With that comes a sense that the medium is "uncontrollable" by the system. In other words: when you watch TV, you expect/understand that you are being fed/manipulated. But when you are "on the internet" the sense is that you yourself are in control of what you consume or produce there. And, of course, that is not the case, and in fact: internet/social media are exponentially more successful at, and adaptable to control and manipulation!
So, my point is: yes, we do have the responsibility.
But we also need to understand that anything we put out there, or what we choose to consume (how we use the medium), is completely malleable by somebody/something else.