YouTube, one of the world’s most popular websites, was offline for more than an hour due to a technical fault on Thursday.
The video sharing site, owned by Google, was the fifth most popular website in the US in February, according to Nielsen, attracting more than 108m unique users.
In January, attacks on Google’s systems that the search company said came from China prompted a partial withdrawal from that market.
On Monday, Google began diverting searches on its Chinese site to its Hong Kong arm and stopped censoring the results. Many feared that the move could prompt reprisals from Chinese officials, who denounced the decision as “totally wrong”.
There was no indication that YouTube’s outage was caused by Chinese hackers, however. Although Google’s “cloud computing” infrastructure is famously robust, YouTube said an internal problem was responsible.
“YouTube is up again following a technical issue which has now been resolved,” Google said in a statement. “We know how important YouTube is for people and apologize for any inconvenience the downtime may have caused.”
On Wednesday Wikipedia, another top-ten site, went offline for several hours due to cooling problems with its servers. In a blog post yesterday, Wikipedia apologised for the outage and explained why its English-language site went down.
“Due to an overheating problem in our European data centre many of our servers turned off to protect themselves,” it said. Wikipedia’s “failover switch”, whereby traffic is diverted to another data centre, then broke, meaning users were unable to reach the site.
Last December, Twitter was briefly hijacked by a group claiming to be the “Iranian Cyber Army”. The short-messaging site was a popular tool for anti-government activists in Iran last summer.