More than six million people have signed up as blood donors on Facebook's blood donations feature in India making it the largest online blood registry in the country a company executive said on Thursday. We are part of the team at Facebook that is focussed on building safe and supportive communities. We saw a lot of activity on the platform where people sought help regarding blood donation. This was our motivation to launch the initiative Hema Budaraju Product Manager Health at Facebook told IANS. Facebook organised its 'Legendary Blood Donation Drive event with non-profit NTR Trust in Hyderabad on Thursday.