The teens behind the Mirai botnet
"Telnet, an outdated system for logging in remotely."
This comment from the article bothered me. No evidence was given as to why it is outdated. I did a little digging to find that Telnet is vulnerable to several different attacks, but all of it can be mitigated by Transport Layer Security (TLS) security and Simple Authentication and Security Layer (SASL) authentication. Of course many devices don't support TLS and SASL. If a device does support the newer standards I think it's wrong to consider it outdated.