I'm quite sure that you're talking about this berry1
http://www.monsterfishkeepers.com/forums/showthread.php?550201-Live-feeding-as-a-crime
I know your point really is true, what's the difference between a cockroach and a fish when you offer it to the fish? Well really, there's a lot.

But I on the other hand, I go with 50% live food/50% pellets (still prepared than mine), so I would know what's the effect of both, well I won't walk about which is better or not but go with the OP's thread.
Technically if your State says that it's illegal to feed feeder fish to your fish, then it's wrong, why? Because it's illegal, but even so, I can't see the basis for it really... ( don't support this one! civil disobedience for this case!)

kidding.
second, if you just got it from sources which can be a breeding grounds for pathogens, parasites, or anything harmful, quarantine procedures must be followed also, catering the feeder fish as a real pet is priceless, just imagine that they're your food then you just let them be without even giving them the right care for them to be more delicious. Yum yum.
third, it's wrong if it's really for your entertainment only, I mean you would like to see a school of RBP ripping out a large catfish leading your tank dyed in red. UGh ugh... that's totally creepy. But still it's my opinion as well.