Bias

Talking about bias while talking about blogging is rather pointless, really.
I mean, a technology who's most basic point is to allow people to publish their opinions and stories online will be nothing but biased.
There is no screening process involved with getting a blog. Anyone and everyone with an internet access and the ability to type can start their own blog.
Bias will be inherent in any blog, whether the blog is about music, politics, movies, the environment or just a journal blog. People write mainly from opinionated stand points, not journalistic ones. The difference between reading about current events from a privately run blog and a newspaper would be that journalists are meant to write just the facts of the events. While bias does have a way to seep into journalism, they at least attempt to remain impartial. With bloggers, there is no pretext of unbiased opinion. For example, this blog is written from a group of liberal minded writers.

While this one is written from a conservative stand point:

Music centered blogs are usually very biased with the kind of music they follow and talk about. Most music blogs focus on one kind of music, indie music blogs are popular, bloggers enjoy finding bands or artists before they become popular.
Aside from the fact that all blogs contain their own bias, blog services contain bias of their own. Blogs promote the idea that every blogger's opinion is interesting enough to be heard.