Its more than just people seeking out what they want to hear. It's the media packaging the materials in ways that purposefully mislead or create a sympathy towards whatever ideology it's biased towards. It's often done subtly but sometimes it's blatant. My two examples were one of each, but both were definitely reflective of specific bias.
Often it's done because a certain part of our society berates those who disagree with their "educated" views as small minded, or they presume that their view is the only correct view.
You can see media bias pretty easily if you look at sites using
critical thinking skills. Are they pushing an agenda? Do the reported facts and story line up with the story Headline. (Headline writers often aren't the same as those who write the stories, and their job is to draw in people to read the actual story, so if a headline is grossly misstating the facts reported then some form of bias may be at play). Does a site/media outlets facts vary from other reputable sites (not other mainstream media that all get their stories from one or two sources).
Media Bias happens from both sides. You hope that by searching and reading you can find out the "truth" (the truth is out there Mulder). But I am more and more skeptical that any of the fourth estate can be seen as more than lapdogs.