If you do something on the block chain with your Bitcoins it's save.
Just that the only thing it does is making sure you can send or retrieve a Bitcoin securely but that you need other security mechanism to make sure the trade is protected gets ignored.
Like every trade involving something outside the chain is still not save.
Buying Bitcoin, selling Bitcoin, trading a Bitcoin for a service.
If you do something on the block chain with your Bitcoins it's save.
Just that the only thing it does is making sure you can send or retrieve a Bitcoin securely but that you need other security mechanism to make sure the trade is protected gets ignored.
Like every trade involving something outside the chain is still not save.
Buying Bitcoin, selling Bitcoin, trading a Bitcoin for a service.