Apparently they used facebook to incite backlash against the Indian government to bully them into allowing their Internet.org initiative to continue there (essentially a stripped down, anti-net-neutrality version of the internet which only allows people to use facebook and a couple other sites).

This was mentioned in Careless People. It seems like they wanted to use facebook as an electoral tool pretty early on because it gives them leverage over politicians. They might not have been deliberately involved in CA, but this is probably exactly what they wanted