In his commencement address to Harvard, his sort-of alma mater, Facebook founder Mark Zuckerberg pitched ideas including online voting and universal basic income and urged the class of 2017 to tackle a number of societal challenges, including climate change and disease.

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The address is, of course, posted on Facebook .

Zuckerberg started his remarks by musing that he's an unlikely choice, as he dropped out of Harvard. (He's now Dr. Zuckerberg, thanks to the honorary degree conferred up on him).

He challenged graduates to find purpose and to think big.