The OCS 1.9 version improves some social media features to OCS:

The supporter of the initiative will be able to share his vote with his Facebook, Twitter or Google+ social network after he supported the initiative.

As an organizer, you will need to configure the Facebook, Google + and Twitter urls of your initiative that your supporter may want to refer.

For Twitter,  you are also able to enter a predefined text message for the supporter (that he can change later).

To configure those settings, log to your OCS admin tool, go to Settings and browse the page till you find the social media settings ( Organizer page).