Well, there is always some risk. All we can do is to minimize it. Fiat currencies have its own issues. Some economists say US government will default in the future and value of USD will go down sharply. Others make pessimistic predictions about Euro. What else? You can buy gold, but unless you are going to keep it at your house you have to trust someone to store it for you. You can buy stocks but again you have to trust other people.

Being paranoid is also costly. If you keep all your money/gold/whatever in well secured vault in Swiss bank then you have to go there if you want to spend some money. The same applies to bitcoins. You can choose to trust no one but in such case it will be probably impossible even to buy single bitcoin because how are you going to buy it without taking any risk?

Too much trust is bad and can cost you money. But no trust at all is also bad. It also costs you - time and lost opportunities. In the end everyone should find his own golden mean.