What is our motivation?

I attended the California League of Middle Schools (CLMS) technology conference in Monterey, California this weekend. This was an awesome experience, an opportunity to learn and mingle with some really cool people, and I enjoyed myself enormously.

The conference, however, is not the subject of this post.
The real subject of this post is a realization I had on the flight home.
As the plane approached Los Angeles, I was looking out the window at the landscape below. I don't live in LA, but being a Southern Californian the scene was at least somewhat familiar- rows of orderly streets, houses neatly laid out in blocks, swimming pools in many of the yards.
As we flew over the LA River, however, I noticed something. Well, it's not completely accurate to say I "noticed" it at this time, because it's something I've seen hundreds of times in the past: graffiti painted on the concrete walls of the river channel. Nothing terribly offensive, true, but still my first thought was, "[Expletive] taggers! Why do they have to do this? Are they so arrogant that they think everyone needs to see their names?"
Then it hit me: taggers have the same motivation for what they do as bloggers!
"Wait a minute!" I can hear you say. "Taggers are vandals, they destroy public and private property! It's against the law! Bloggers don't do that!"
True, and I certainly didn't mean to imply that bloggers are equilivant to taggers. I only meant that they have the same fundamental motivation behind their actions- a belief that they have something worth while to say and a desire to let that voice be heard.
While we have decidedly different approaches to realizing this desire to be heard, the essential motivating factor is the same. I would much rather see taggers utilizing a less-criminal outlet for their expressive desires, but understand now what it is they are trying to accomplish, which is the same thing I am trying to accomplish right now; make my voice heard. I don't agree with (or, quite frankly, understand) most of what taggers "put up," but neither do I agree with, or understand, a lot of what other bloggers post, but I now believe that we are all engaged in the same basic activity, and I think, the next time I see tagging, I'll be less likely to respond the same way I did today. I'll understand the intention, and complain about the execution.