Wanting an open discourse with other viewpoints is not a "bully's idea"; it is a fundamental part of a rational thought process. The converse is creating an echo chamber.
In media, an echo chamber is a situation in which information, ideas, or beliefs are amplified or reinforced by transmission and repetition inside an "enclosed" system, often drowning out different or competing views.
How it works
Observers of journalism in the mass media describe an echo chamber effect in media discourse. One purveyor of information will make a claim, which many like-minded people then repeat, overhear, and repeat again (often in an exaggerated or otherwise distorted form) until most people assume that some extreme variation of the story is true. A media conglomerate that owns multiple media outlets can produce the same story among "different" outlets, creating an illusion that a media consumer is getting information from different sources.
Spreading false information
Similarly, the term also refers to the media effect whereby an incorrect story (often a "smear" that first appears in a new-media domain) is reported through a biased channel, creating a media controversy that is subsequently reported in more reputable mainstream media outlets. These mainstream reports often use intermediary sources or commentary for reference and emphasize the controversy surrounding the original story rather than its factual merits. The overall effect often is to legitimize false claims in the public eye through sheer volume of reporting and media references, even if the majority of these reports acknowledges the factual inaccuracy of the original story.
How it impacts online communities
Participants in online communities may find their own opinions constantly echoed back to them, which reinforces their individual belief systems. This can create significant barriers to critical discourse within an online medium. The echo chamber effect may also impact a lack of recognition to large demographic changes in language and culture on the Internet if individuals only create, experience and navigate those online spaces that reinforce their world view. Another emerging term for this echoing and homogenizing effect on the Internet within social communities is cultural tribalism. The Internet may also be seen as a complex system (e.g., emergent, dynamic, evolutionary), and as such, will at times eliminate the effects of positive feedback loops (i.e., the echo chamber effect) to that system, where a lack of perturbation to dimensions of the network, prohibits a sense of equilibrium to the system. Complex systems that are characterized by negative feedback loops will create more stability and balance during emergent and dynamic behavior.
What Does This Mean?
You do not have to agree with someone to make their point of view valuable. Arguments against your point of view can strengthen it, adjust it, or make you change it. That is part of rational thinking. Placing yourself intentionally in an echo chamber is not conducive to rational thinking, or to producing sound decisions. A great book that I would recommend discusses this in a succinct and clear manner: http://www.amazon.ca/Mistakes-Were-Made-But-Not/dp/0156033909
Bullies don't attempt to have a dialogue; they attempt to drown out the voices they don't want to hear.