The numbers are quite alarming. According to this Forbes article, while the number fluctuates based on the market price and the published amount at the authors time of writing, these are the quoted amounts that have been lost due to hacks as well as human error.
DAO - $53 million
Bitfinex - $72 million
Parity - $30 million + $275 million
Mt. Gox $460 million
Coincheck $530 million
It seems that this quote has only the biggest hacks, I can recall many more hacks . I found it very interesting that such big exchnages are not working harder on their security measures. Also maybe this will stop slowly when we are going towards decentralized exchanges.
And what about how much money is lost because of telegram an twitter scams and scam ICOs..