This is what karma scores on site like this or Reddit try to replicate.

Not really, because such sites really only use upvotes/downvotes as a ranking mechanism. There's theoretically a lifetime upvote/downvote counter (ie. your karma), but other than a number that shows up on your profile, it doesn't have any real impact. You don't really develop a "reputation", for instance your comments get more or less visibility based on your previous commenting history.

	▲	al_borland 9 days ago \| parent \| next [-]
		There were a couple occasions on Reddit where someone replied to me in seemingly bad faith. I looked and they had negative karma. As a result, I didn’t engage. But I will agree that it’s far from perfect. It’s also similar to the bar example. A reputation is built one person at a time. It takes a while, with repeated bad behavior, to build a bad reputation with the entire staff or regulars.
	▲	randycupertino 9 days ago \| parent \| prev [-]
		> other than a number that shows up on your profile, it doesn't have any real impact. Certain subreddits you can't comment on until you have a minimum # of karma, some other subs auto-ban you if you contribute or subscribe to other subs.

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2OEH8eoCRo0 9 days ago | parent | prev [-]

Yes. And fails. Trolls don't care about karma and can run about being a dick until they're finally banned (possibly years later) rinse and repeat with a new account.