"Of course the internet is full of lies. But so are most lawyers and a large number of witnesses."
Witnesses do lie, without a doubt. But, in court, lawyers don't. If they did, and it was discovered that they had lied, they would have the proverbial book thrown at them - not forgetting the cost to the public purse of a possible retrial.
And the suggestion that you go out and trawl the internet to find out what you can about the case is just stupid. If the information is pertinent, it will be used as evidence, either by the defence or the prosecution. If it is not, it won't. And if it's not been discovered by either the prosecution or the defence, why on earth do you think that a quick trawl on the internet by a juror will turn it up? Must more likely it'll turn up some information which makes it impossible to give the defendant a fair trial.
(By the way - if the prosecution has some evidence which will help the defence's case, they MUST disclose it to the defence. The defence has no such obligation. It's the job of the prosecution to PROVE the case.)
It is the job of the police to find the evidence. It is the job of the opposing counsels to put each side's case. It is the jury's job to listen to both sides, evaluate the evidence and to make the judgment.