Spam
Following DoS attacks on the ethereum network last year, an attacker has picked an easier target to spam: Ropsten, the ethereum testing network.
Email-forwarding service Composed aims to help the global fight against spam by making senders pay a small fee in bitcoin.
Salesforce has won a patent outlining how a blockchain-based platform can be used to prevent spam or other unwanted emails from hitting inboxes.
The block chain has potential uses beyond storing transactions, but could they pose a risk to bitcoin?