The Face of Evil

How could a grown man try to hurt little babies like these?

Evil lurks behind many different faces.  I saw one this week.  Fortunately, I happened to be looking out my bedroom window as an elderly man walked across the grass toward the groundhog hole/home that's right next to the building I live in.  I suppose he saw the groundhogs frantically scamper into their home once they saw him coming.  He began by making a sudden move to frighten them.  Then he picked up rocks and began throwing them at point blank range into the hole at the baby groundhogs: not on my freaking watch.
"What are you doing?"  I yelled out the window to him.
He stopped throwing rocks and looked around to see who said that.  He saw me at the window.  He seemed guilty; like he'd been busted.  He smiled and said something that I didn't entirely catch, but I think he said something about how they damage the ground or some such garbage.  They're on this Earth, so they obviously belong here, and they have the right to live here in whatever way they see fit.
My adrenaline was pumping, so I don't remember if I told him to leave the animals alone.  I think I did, but my memory is a little fuzzy.  This guy's cruelty blew me away.  I think he's just a bully.  Now he's old and feeble, so he can't bully someone like me, so instead he terrorizes some baby groundhogs.  What's even worse about it is there's at least one bully among the babies.  One time, I watched from my window as a baby groundhog kept trying to get into the hole, but it seemed like at least one of the babies wasn't letting her enter.  So it's possible that one or more of the babies was having trouble getting to safety while this coward was throwing rocks at them.
Today, I heard a bunch of kids running around.  They were chasing and terrorizing rabbits.  I didn't like it, but as long as they were just chasing them, I'd figured I'd stay out of it.  When I saw that the largest of the kids was throwing rocks at a rabbit, I knew it was time to intervene.  I went downstairs and walked toward the kids.  They noticed.me.
"Don't hurt any animals," I said to them.  "Don't throw anything at them."
The largest boy said, "Okay."  So I went back inside.
I realize I can get into a lot of trouble, but I don't want to passively watch as people try to hurt animals.  I'm against fighting; it's stupid.  But if I see someone beating an animal, my plan is to tell them to stop.  And if they don't stop, I might have to take action.  And in such a situation, it's highly likely that I would be the one in trouble with the police.  But our legal system exists mostly to protect people: not animals.  Pets have some rights, though they are obviously abused on a massive scale.  Wild animals and "food" animals like pigs, cows, and chickens have very little in the way of rights.  And all I'm really referring to is the right to not be beaten, tortured, and killed.