Would you want to be a witness being interrogated by a hostile lawyer, and knowing that possibly thousands of people are getting their kicks watching you?
Would you want to be a defendant subjected to such a hostile interrogation, knowing that many of the people watching will not bother to watch the defence case and so will assume you are proven guilty even if you are found innocent?
Trial by newspaper is bad enough, but there will now be trial by social media with none of the minimal constraints that the newspapers have. Everyone chipping in with their pet theories, with no regard for legal process. Remember that bloke that got falsely accused of the Boston bombing because lots of amateur detectives analysed the videos?