Unfortunately because cryptocurrencies are completely online, they can be manipulated by hackers who know about your bitcoins. This is why many people say the first rule of bitcoin is to not talk about bitcoin. You never want anyone to know what type of cryptocurrency you use and how often you use it. You can lose it all with just one text message.
One online user recently posted a story on the website Medium about how they lost $8,000 in bitcoins. It all started with one text on his cellphone that appeared to ask him about his cellphone service. From that point, it escalated. Before the user knew it, his account passwords had been changed and $8,000 had been stolen from his account. He was completely blindsided. Furthermore, because there is no bank or insurance company that can be held responsible, there is no way to retrieve the money.