I nominate Patrick Ball , director of the Human Rights Data Analysis
Group  and lead on Martus (which is FLOSS) .
I've never heard him talk but I admire the project, which is about
gathering and analyzing enormous amounts of data and making it accessible
and understandable to make the world a better place, like we do---except
they do it about torture and human rights violations.
Here's a video of him leading a panel at Berkeley recently:
"Benetech HRDAG develops database software, data collection strategies,
and statistical techniques to measure human rights atrocities. Our
technology and analysis is used by truth commissions, international
criminal tribunals, and non-governmental human rights organizations around
the world. Our analysis identifies the trends and patterns which is the
evidence of crimes of policy. "
"Martus is a secure information management tool that allows you to create
a searchable and encrypted database and back this data up remotely to your
choice of publicly available servers. The Martus software is used by
organizations around the world to protect sensitive information and shield
the identity of victims or witnesses who provide testimony on human rights
abuses. Martus is the Greek word for witness."
William Denton, Toronto : miskatonic.org www.frbr.org openfrbr.org