Ittay Eyal and Emin Gün Sirer are quoted in Forbes regarding potential abuses of Bitcoin's blockchain, the public ledger of all Bitcoin transactions. Eyal argues that botnet owners would not be inclined to use it for malware communications due to speed issues. Sirer notes that there are serious dangers if the blockchain were used to control malware: "instructions can be encoded in a way that looks opaque to everyone except the malware itself. There is no good solution for this; it’s a price we have to pay for freely transmitting information".