  Ten years ago, DARPA launched the 'Network Challenge', more commonly known as
the 'DARPA Red Balloon Challenge'. Ten red weather balloons were fixed at
unknown locations in the US. An open challenge was launched to locate all ten,
the first to do so would be declared the winner receiving a cash prize. A team
from MIT Media Lab was able to locate them all within 9 hours using social
media and a novel reward scheme that rewarded viral recruitment. This
achievement was rightly seen as proof of the remarkable ability of social
media, then relatively nascent, to solve real world problems such as
large-scale spatial search. Upon reflection, however, the challenge was also
remarkable as it succeeded despite many efforts to provide false information on
the location of the balloons. At the time the false reports were filtered based
on manual inspection of visual proof and comparing the IP addresses of those
reporting with the purported coordinates of the balloons. In the ten years
since, misinformation on social media has grown in prevalence and
sophistication to be one of the defining social issues of our time. Seen
differently we can cast the misinformation observed in the Red Balloon
Challenge, and unexpected adverse effects in other social mobilisation
challenges subsequently, not as bugs but as essential features. We further
investigate the role of the increasing levels of political polarisation in
modulating social mobilisation. We confirm that polarisation not only impedes
the overall success of mobilisation, but also leads to a low reachability to
oppositely polarised states, significantly hampering recruitment. We find that
diversifying geographic pathways of social influence are key to circumvent
barriers of political mobilisation and can boost the success of new open
challenges.
