I don't know of any PoS coins that were attacked. Contrary to PoW, PoS is used for a very general category and differences between multiple versions are great. Many don't even have slashing making them a trust-based system (like Cardano) and I don't think they should be considered proof of stake - because without slashing nothing is actually at stake.
Additionally except for eth all have the fundamental problem of extremely centralized distribution. This [1] extreme centralization is representative of new VC coins. That tiny sliver of 'Coinlist (unlocked auction) 4.3%' is the only part that was available to non-insiders.
Yes, I'd be curious what some PoS coin experts have to say about the centralization concern of PoS, and how network security and uptime is guaranteed in a PoS network that doesn't have slashing.
I'm also wondering about the resiliency of PoS. The PoW used in Bitcoin has demonstrated resiliency against attacks, and none of the attacks have been successful so far, that I know of.
>The PoW used in Bitcoin has demonstrated resiliency against attacks
Multiple PoW coins have been successfully attacked, like ETC. Because they are already on GPUs there's no fix - just hope it doesn't repeat. Those successful attacks prove that any attack on PoW is only a question of external resources (sha256 ASICs for btc).
It's also surprisingly hard to profit from a 51% attack on pure speculation coins like btc or etc because next to zero actual economic activity is happening on them, which is why such attacks were rare and small in scope. The best you can actually do is to try to double spend an exchange. If they were actually used for real commerce profit becomes much easier. It could also become a military goal - if Iran relied on a PoW-coin for its economy, blocking their coins would destroy their economy.
This is one of the reasons why ethereum absolutely must switch to PoS - PoW is extremely insecure for smart contracts because there are many more ways to profit from an attack, like censoring price updates for defi.
I'm aware of the ETC attacks. I don't think ETC can really be compared to BTC though. The ETC network is composed of the idealistic (or maybe stubborn) folks who didn't want to switch over to the new ETH chain after the DAO hack. I'm not saying ETC has no merit, but it didn't have the same network resilience due to the split.
Seems like you know a lot about PoS, would you be willing to check out my other comments on this post (https://news.ycombinator.com/threads?id=swensel)? I've covered some concerns / questions that I have about PoS that maybe you can answer in more detail.
Additionally except for eth all have the fundamental problem of extremely centralized distribution. This [1] extreme centralization is representative of new VC coins. That tiny sliver of 'Coinlist (unlocked auction) 4.3%' is the only part that was available to non-insiders.
[1] https://icodrops.com/wp-content/uploads/2018/04/Solano-token...