Large numbers of U.S. Web users were unable to access their favorite sites early on Friday morning. “Twitter, Spotify and Reddit, and a huge swath of other websites were down or screwed up this morning,” Gizmodo reports. “This was happening as hackers unleashed a large distributed denial of service (DDoS) attack on the servers of Dyn, a major DNS host.” As such, “It’s probably safe to assume that the two situations are related.”