SarcasmMode, I don't know where you get the idea that gang members aren't entitled to protection in prisons, but you're wrong.
Can you really not see that it is never acceptable to condone violent criminals beating up other prisoners? It's not good enough to suggest that they shouldn't have committed the offence if they didn't want to be beaten up - after all, the people doing the beating are also deeply horrible people, why should they be given carte blanche to enjoy themselves maiming others?
Where does the principle stop - if it's OK to beat up paedophiles, why isn't it OK to beat up rapists, murderers, people guilty of serious physical assaults, kidnappers, hijackers, traffickers, drug dealers, bank robbers etc etc? Should we just thrown people into prison and let them fight it out till several end up dead? Where does that leave people who are wrongly convicted?