Have you ever heard about the information that Bitcoin had been hacked in the past? 
For me at least I dont think or need to have a news article to know that bitcoin has been hacked or can be hacked. Just the fact that it exists on the internet, digitally and electonically a master hacker or someone competent enough can really pull this off as it is wrll within their scope and dimension and we can only do so much and provide ourselves with enough cyber security to get by