Is it legal to fight back against dangerous drivers?

I live in Southern California. I can't even begin to count the number of times people have pulled stunts that have nearly run me off the road or into oncoming traffic. They do the same things day in and day out on these streets, since they know police never patrol them. So, with that in mind:

1.) Is it legal to keep a dash mounted camera in your car as a private citizen?
2.) If footage of a lunatic running wild behind the wheel is sent to the authorities, are they able to act on it - provided the license plate is clearly visible?
3.) Would footage like this be legal to post on the Internet? (Youtube)

1. People driving on a public highway have no expectation of privacy, so you can legally record them.

2. The vehicle alone may not be enough, the police need to identify the driver to take action.

3. Again, there is no expectation of privacy, so you could post the video publicly.

Yes to all three. The determination would be left up to the authorities as to weather or not they would pursue any legal actions unless there were a clear violation (or causing an accident). They would probably check your video for authenticity as well. That is an excellent idea by the way! I have the same experiences and will probably do the same thing. Thanks for the idea.

The best tool you have to fight back is your cell phone; dial 911 and be ready to tell the operator what happened, where they are and what direction they're going.

please petition Joe Arpaio to bring the weight of his authentic self to your world Maricopa Sheriff Office AZ he has cleaned up our streets and we dont need him anymore

No - this is scary 1984 ****.