One that I only learned about a few days ago involves an investor who was erroneously shown a -$700K balance on his Robinhood account and then killed himself as a result[0].
Back in September of 2019, I made a deposit into Robinhood. The next morning I received an automatically generated email saying that the deposit had bounced and that my account was now limited. I checked my bank account and saw that the funds had indeed been removed. The email included the ACH error code "R26", which corresponds to a malformed ACH file. I quickly learned that every single deposit on that date had failed [1].
No worries, I thought, I'll just email support and let them know. Unfortunately their support was completely useless and did not follow through with what they said.
I switched to TD Ameritrade (and the thinkorswim platform) and have not looked back.
I think Robinhood needs a sort of Uber-style restructuring. It's clear they do not care about their clients.
[0] https://www.forbes.com/sites/sergeiklebnikov/2020/06/17/20-y...
[1] https://www.reddit.com/r/RobinHood/comments/d0joa2/solution_...