An online assault on a California company knocked out some of Vodafone's internet services yesterday.
Hurricane Electric, which provides Vodafone's international internet services, was struck by a denial of service attack around 11am.
Such an attack involves an organised group of web users all accessing a computer server at the same time.
This disrupts services and usually causes the server to buckle under the extra traffic.
When Hurricane Electric went down, Vodafone users were unable to gain access to some websites in the United States.