YouTube - Harmless to Broadcast Yourself?

YouTube, as we all know, is a website that allows people to upload videos onto the internet, onto this website. This website was created in 2005, which is not that long ago, and has greatly increased in popularity since then. Anyone can upload practically any video (except something like porn) so that anyone that goes on YouTube can view it. That means there is a wide variety of videos out there. You can search the word "dog" and hundreds of videos with dogs or related to dogs will pop up. You can view funny videos, informative videos, scary videos, just plain disgusting videos, etc. But is it harmless to allow people to broadcast themselves (and others..)? Does this website serve any productive purpose? That is what I would like to analyze in my term project. I want to discuss the different types of things people upload on YouTube such as videoblogs, embarassing videos of friends, etc. and if there is any harm in such things or if it actually serves any good purpose.