Earlier this morning, our DNS provider (Dyn.com) saw a largescale DDoS that affected DNS resolution. This caused API calls to fail intermittently as the domain name(s) for block.io became unresolvable.
The issue affected a large swath of Internet-based services, including Netflix, Twitter, PayPal, Braintree, etc.
The issue was remedied around 9am Pacific time by re-routing the DNS through an alternative provider.
We sincerely apologize for the inconvenience this has caused, and are taking steps to distributed name-resolution to multiple providers going forward.
For some information on this attack, see https://krebsonsecurity.com/2016/10/hacked-cameras-dvrs-powered-todays-massive-internet-outage/