Red John, although having a sophisticated cult like following, IS 1 single individual male and not a number of people posing as te same individual. We know this due to a) the discription of the blind woman as to him being a male of average height , loving classical piano music, soft but rough hands , etc. b) his voice we hear over the radio strapped to Waynright, c) always referred to as he or him and d) this last episode "red barn" proves that he was in fact a member of visualize who worked on the farm.
The last episode also proved that Red John was or still is a member of Visualize . Which would help explain why Bret Stiles told Jane he had privlaged information on Red John & would also explain part of Red John's having a large organization & resources like Visualize.
We also know that Visualize has the 1 mole inside te CBI as revealed in Red Barn, but also Van Pelt who seemed to open up to Stiles while in custody, had the outburst while questioning the priest, where she defends Visualize, is obviously a suspected mole now as well.
Bret Stiles may not be Red John, BUT there is no doubt in my mind that Stiles knows who Red John is & still has communications with him.

The priest Dibuono said that the smile of Red John was already there when the farm was still in operation. A guy who worked there did that. Is the oldest evidence we have of Red John.
Or he did it or it's possible he was inspired by that picture. In any case have connection with Visualize.
We know that many people who worked there were criminals, drug addicts and cruel to animals. People who had nothing to lose, forgotten by their families, without civic ideals and moral values.
The best people you can manipulate, being capable.

MY QUESTION IS:
We know that the farm was losing a lot of money. Visualize is a powerful company, why Brett Stiles would want to lose money on a stupid farm because of three complete idiots in business??

I am convinced that Stiles had thought the farm as an experiment to see how people express their dark side, living in those particular conditions.
I believe that Stiles is Red John, a serial killer built by himself, that he was inspired by what was happening on the farm. The slogan of Visualize is: be the best side of you (or something similar).
And Red John is actually just a serial killer very self-disciplined and this has not always allowed to be taken. The fact that the Visualize hiding many of its stock is significant. Patrick shook hands several times with Stiles. I remember that Stiles brought Lorelei out of prison; if Red John wanted her there, why he would make her escape so easily?
And Stiles is a very clever mentalist, maybe better than Jane.

I think Brett Stiles feel like a god, and so he could be very beneficial  and very evil at the same time with the people. It's perfectly self controlled, clever, very powerful, in touch with powerful people, protect by a sects that worships him.
What else?

I think that red Jon is not one man but a cult devoted to murder

Think about it all his "connections" with high end people

That's why they can't catch him because there liking at this

The wrong way

Not an accusation theory, but a theory to disprove every other theory that Patrick Jane is Red John.

http://www.youtube.com/watch?v=fgvXfZK9dnw

This video shows Rosalind speaking to Jane whilst RJ is there in episode 13, "Red is the new black", season 4. 
Possible argument to this is that she initially said "Roy CAME to see me" suggesting she lied about him being there. I don't think we should read into every single word though. I personally think it's Brett Stiles. 
I mean who's a better Red John than Alex DeLarge, the classical music loving, original sociopath, all 'cured' and grown up!!

all evidence points to him

He knows red John and won't give up the security cams

I am a huge fan of the mentalist from day one. I go back and forth with my suspects lol. Could be so many different people. One of my top suspects is brett stiles especially the whole kristina frye thing. My sister has jus recently started watching the mentalist by borrowing my dvds. She recently watched the episode where brett stiles gives the address to kristina's whereabouts. I mentioned how I thought it was him because he knew the location and she put something interesting to me that I had never thought of......when we are first introduced to visualize they mention that all their members have to make confessional videos about all the bad things they have done (and only senior staff have access to these videos). What if red john is a member of vizualise and on his video he made mention of kidnapping kristina frye (bad thing he has done) and also mentions her location. As brett stiles is the most senior staff it would make sense why he knows her location (watching the video) and also makes sense why he also said to patrick i know more than you and red john (watching confessional videos).....just a thought!! :)

Another thing I wanted opinion on - in the episode where the team goes to the location of where the dead frozen man has been laid with the flowers, lisbon notifies everyone on the phone however she is not there with them when they investigate and this is the same time bosco and his team are murdered by rebecca. Where was she????