Facebook users have their last chance today to vote on the way the social networking site handles user data.
The site sparked fierce criticism in February when users complained about changes to terms and conditions.
The changes appeared to give Facebook ownership of user data, including pictures, video and profile information - even after users deleted their accounts.
Launching a vote last week on a new set of changes, Mr Zuckerberg said: 'The Facebook community has grown a lot over the last few years and at 200 million this population would be the fifth largest country in the world - just ahead of Brazil.
'A community that large and engaged needs a more open process and a voice in governance.
'That's why a month ago we announced a more transparent and democratic approach governing the Facebook site.'
The week-long vote, which gives users the choice of continuing with existing terms or opting for a revised set of rights and principles ends today at 7.59pm.
It followed a 30-day comment period which helped to shape the new documents.
The revised principles state: 'People should own their information. They should have the freedom to share it with anyone they want and take it with them anywhere they want, including removing it from the Facebook service.'
The principles also say Facebook should make its 'purpose, plans, policies and operations' publicly available and should apply a 'town hall process of notice and comment and a system of voting' before making changes to its terms.
However, the principles are not legally binding.
They reflect the philosophy and values to which we aspire rather than specific commitments between Facebook and our users,' Facebook stated in response to comments from users.
Users can vote on terms by going to the Facebook Site Governance site at http://apps.facebook.com/fbsitevote.