Internet technology and social networks are becoming an increasingly important part of dissenting political engagement. In response, abusive regimes take steps to impede the ability of dissidents to access the internet and/or use the internet as a tool to track down and suppress dissenting opinions (e.g. the Egyptian revolution, recent riots in Venezuela, independent online Cuban journalism...). That's made easy by the hardware on which online communication is built: central, often state-managed.
A way to communicate without exposing protesters to harm is a critical component of the ongoing fight for human rights.
Decentralized hardware and private channels make Spark's implementation of a wireless mesh network uniquely good at achieving just that. At no point does an oppressive regime control the means of communication, and in no way can an oppressive regime track down and silence people who want to make the world a better place.