The trouble w/ sentiment analysis is that you really need a model trained for the domain. A model that is good for product reviews is not going to be good for stock market discussion boards or angry toots. I’d badly like an angry toot filter but I’d have to find about 5000 angry toots and 5000 non-angry toots and that is probably about a week’s worth of psychologically difficult work. (The whole point is that I don’t want to see the angry toots)
“Thoughtless”, “low-effort” comments on HN might not be so debilitating to look at though but given that “bad” is in the eye of the evaluator you probably would have to look at a lot of them to make a model.
I also want something that disappears images that are mainly text, whether it is a T-shirt with a slogan designed to piss people off or a screenshot from some other social media site it is usually crap.