2. there is a fork in the block chain, or major systematic problems with the whole coin system
Only seen it happen once, I didn't lose any coins, maybe mining pools lost some mining effort, it was fixed in less than 24hrs.To lose your coin in hard fork, you need to:
1. Receive a tx in that short period of time (before you notice the hard fork).
2. The tx is confirmed in one fork, but not the other fork yet.
3. The sender double spend the tx in the latter fork.
4. The latter fork is the longest chain (main chain).
So, for the majority, no coin will be lost in an event of hard fork.
typical way of online wallet scam is that the "website hacked, and all coins stolen".
Sounds so much like inputs.io lol.
