For them, using a DDoS mitigation service might be harder than it seems. Their project, "Collateral Freedom", depends on having a set of web frontends with some special properties. Namely, 1) the provider of the said frontends must be willing to ignore takedown / access restriction requests from (Chinese, Russian, etc) authorities, and 2) the access to those frontends can't be easily blocked by the Great Firewall of China / Russia / etc without causing massive problems to some unrelated widely used services.
(full disclosure: I do devops for one of the Russian sites that is currently mirrored by Collateral Freedom)
(full disclosure: I do devops for one of the Russian sites that is currently mirrored by Collateral Freedom)