Denial of service (DoS) and distributed denial of service (DDoS) attacks are increasingly common phenomena, used by a variety of actors—from activists to governments—to temporarily or indefinitely prevent a site from functioning efficiently. Often, the attack saturates the target with server requests designed to flood its bandwidth, leaving the server unable to respond to legitimate traffic.

Though the owners of major sites often have the resources to fend off or even prevent such attacks, smaller sites—such as those belonging to small independent media or human rights organizations—are sometimes permanently disabled due to a lack of resources or knowledge.

This EFF guide aims to assist the owners of such websites by providing advice on choosing an appropriate webhost, as well as a guide to mirroring and backing-up their websites so that the content can be made available elsewhere even if their site is taken down by a DoS or DDoS attack.