  TV White Spaces has recently been in the interest of the networking community
as an alternative to alleviate the spectrum crunch, incentivizing the need to
understand the dynamics of congestion of the occupied spectrum and the
quantification of the free spectrum. In this respect, many regulatory
organizations may provide references for the legal allocation of the spectrum
and therefore allow primary and secondary users to plan their deployments. In
this article, we present the motivations and challenges to collect spectrum
measurements as a global challenge. We discuss a prototype to massively collect
spectrum footprints at low-cost to make it available to communities.
