apparently the Starfleet law against transporting dangerous animals is “twenty years in a rehabilitation colony” 

that’s….. a lot……

oh starfleet got gulags?

Starfleet is military, of course they have gulags. It’s just that they’re fully automated luxury gulags, because Star Trek.

And no, it’s not a lot. Once you’ve seen an alien predator devastate an underdeveloped civilization’s entire planetary ecosystem, you too will drop the full wrath of the Federation’s legal system upon transgressors.

there’s no specification that the dangerous animal need be a predator

the line comes up in reference to tribbles and says only that the law is against transporting “an animal proven harmful to human life”… twenty years on an alien planet

look I’m all for preventing the spread of invasive species but twenty years confined on an alien planet for transporting something so vaguely defined as to describe everything from an aggressive dog or a grain moth is A Lot