There are legal ways to catch bass, and netting a bunch of fry certainly isn't one of them. In most states, it is illegal to net any type of gamefish. Also, many bodies of water have size limits for bass. To aquire one legally you would just have to make sure the body of water doesn't have size limits, and you must generally use a rod and reel. Even a 3" bass can fit small lures and flies into its mouth.
Fishing isn't a bad thing. Responsible anglers have very little impact on the environment. Fish don't have the receptors in their brain to feel pain, so the hooks dont hurt them like it would us. They still feel the hook, but. its different for them.
Maybe it was a small infraction, but it doesn't take many people like that to ruin a good thing. It also doesn't set a good example to or for the other members of this site.
In my current native tank I have a bowfin that I purchased from my lfs, and three green sunfish that I caught at a local pond (the only thing the pond is good for is panfish under 4", because of people who violate the regulations.) I have kept bass in the past, all I had to do was find a pond that doesn't have size limits for bass, and I used a small fly to catch some 3-4"ers. It's pretty easy to go to a sporting goods store (even walmart) and grab a copy of your states fishing regulations, and it can keep you out of trouble.
To the OP, I really wouldn't keep a largemouth bass in that warm of water. Sure, they will seem fine for awhile, but it will shorten their lifespan and cause unnecessary stress, possibly leading to diseases and other problems. Temps from about 65 to the upper 70's are ideal if you really care about your fish. I know that probably wont work for your p bass, but that's why you should do your research first.