US on alert after Friday cyber attacks on Twitter, Spotify

Officials in the United States have said they are stepping up cyber security following Friday's attacks which left several high-profile sites unavailable.

Twitter, Spotify, Netflix and Soundcloud were among the websites affected by the attack on the Dyn servers, and the Department of Homeland Security said it has contacted major communication service providers in order to ensure they are better equipped to deal with future attacks.

The DHS cited the increasing connectivity of devices by the "internet of things" as a potential risk to cyber security.

The sites were overloaded with junk traffic through internet infrastructure company Dyn on Friday, before the issue was resolved on Friday evening.

Security experts have expressed doubts however over the ability of the administration to prevent attacks in such an inter-connected world.

"If you expect to fix all the internet devices that are out there, force better passwords, install some mechanism for doing updates and add some native security for the operating system, you are going to be working a long time," commented TAG Cyber founder Ed Amoroso.