The cause of the crashes remained unclear, but some appeared connected to trouble at a cloud service relied on by companies, although that did not stop the social media rumor and conspiracy mill from going into overdrive.

"We're aware that members are experiencing issues streaming on all devices," streaming television service Netflix said in a tweet at its customer service Twitter account.

Netflix spokesman Joris Evers said that the outage was the result of 'technical issues' at an UltraDNS cloud service provided by Neustar and affected mostly US subscribers.

"UltraDNS is working to address the issue," Evers said. "We apologize for the inconvenience."

Neustar confirmed in a tweet that there was an issue with its UltraDNS.

Internet trouble tracker displayed a list of two dozen websites that were or had been out of service during the day.

The list also included Ameritrade -- an online broker – and The Economist.