This has been covered to death on here, but your accuser is the officer of the court who signs the ticket, not the camera.

For traffic violations where a law enforcement officer initiates a traffic stop, it's clear that the officer witnessed the violation and when issuing a citation, list details such as the make and model of the vehicle, the identity of the driver, the location of the offense and what what the offense was.

If the case is taken to court, the officer will testify that he observed the vehicle committing a traffic violation (the vehicle appeared to be exceeding the speed limit), the supporting evidence of his assertion (e.g., RADAR tracking history), the fact that he initiated a traffic stop, then identified the driver, etc.

He cannot testify, under oath, that he did these things based on video or pictures that someone else took. The person that did take the video can testify to that effect though.

Has there been something more recent than this case?

http://www.thenewspaper.com/rlc/docs/2011/ca-macias.pdf

"Here, Officer Berg did not qualify as the appropriate witness and did not have the necessary knowledge of the underlying workings, maintenance, or recordkeeping of the Redflex Traffic System. The foundation for the introduction of photographical evidence and the underlying workings of the Redflex Traffic System was outside the personal knowledge of Officer Berg.

In absence of a proper foundation, the photographic evidence was held inadmissable."

The officer cannot be the accuser and introduce the evidence if he has no expertise in how the evidence was obtained.

Yes, there have been a lot of unsuccessful defenses based around the camera being your accuser, here's the first one I found.

http://caselaw.findlaw.com/ca-supreme-court/1669146.html