I am a big animal rights person but even I would support removing them (not killing) or at least sterilizing them. We need to protect the natural ecosystem. But they don't seem to be as bad the pythons in Florida as far as fucking up the food chain.
That's really messed up. Any invasive species can have irreversible affects on any given ecosystem. I'd support sterilizing them before killing them, but killing might become necessary. Hippos have been known to topple rowboats and tear a human in half with one chomp.
I think something that looked like Hippos is where humans came from, somewhere way down the evolutionary chain that is.