hackers now are on everywhere without we know who are they. and related with the cryptocurrency, as long as you can keep safe your private key and your wallet, then you are safe. you don't have to be afraid of hackers because if you can save your information with a good security then the hacker cannot break your security. I am not sure that the hacker can change the crypto economy but it is possible as we don't know how high their skill in the technology so we must save our account and don't tell to other people how much money we have.