Are there a lot of hackers now in the crypto's world ? I mean, it a place not totally safe, because of it's quit new. Do you think hackers can change the crypto economy for their own benefit ?
To be honest, hackers have been around since the early days of computers. It has been a threat ever since, but to prevent them from causing damage to anything, security should always be a priority. Hackers can hack computers and whatever accounts but they cannot generate private keys unless they acquire it from your own lack of security. They cannot hack bitcoins as they would have to hack some 13,000 nodes running the public ledger to be able to manipulate transactions.
If you read the white paper of Satoshi Nakamoto on Bitcoins, then you would read a line where he says that it would be more profitable to mine bitcoins legitimately than to try and hack.
Ref:
https://bitcoin.org/bitcoin.pdf