When I lastly moved the whole frickin canteen + kitchen to another place, I had to remove ALL of the recreation items in my prison, and that's where the fun comes in:
My prisoners (about 400) are constantly in a bad mood, because they have no chance for recreation at all, which leads to exactly what I hoped would happen more frequently in the first place: Completely random fights, destruction etc.
I love it so much, once in a classroom a fight between 2 prisoners broke out (completely by chance, about 1,5 hours into the session), one was put down by a guard and instantly 3 other prisoners engaged in the fight, leading to a really interesting and also realistic scenario. You will find prisoners destroying their cells or fight each other in the hall ways or the canteen for no reason (or, if you're like me, pretend one of them eyeballed the other or so
) The danger level is on medium or high pretty much all the time, which spices up the game quite a bit. I have about 5 minor incidents per ingame hour now! 
I have never had a riot break out, though, and I think that is because the threshold for riots was increased and also recreation is no vital need for a prisoner like food would be..
Also, I have 1 guard per 4 max sec prisoners
Seriously try it out! It's really cool if your prison is running a bit too smooth
(I do have phone booths)
