In your Woobox campaign, you can restrict entry to “Once per Facebook user” or “Once per Facebook user per day”. While Facebook does not allow the automatic collection of data from its users, this entry restriction will require that the entrant is logged into a valid Facebook profile. Since Facebook is strict on fake/fraudulent profiles, this is a more secure way to restrict your campaign.
In the Settings tab of your campaign under Participant Limits, turn on entry restrictions, and then choose one of the Facebook restriction option:
You can also accept Hashtag submissions from Facebook in a UGC Contest. Just enable Facebook hashtag entry in the Overview tab and enter the required hashtag(s). Since Facebook only allows you to pull hashtags from your own business page, entrants will need to post a new, public post to your page’s timeline and include your required hashtag(s).