Social Network filters
If you create a custom filter that uses any of the Social dimensions (Social Network, Social Action, Social Action Target), keep in mind that these dimensions apply only to Social interactions (social-hit data).
Some users confuse Social Network in this context (i.e., the social network on which the hit occurred) with the identically named Social Network dimension that identifies which social network referred traffic to your property.
The Social Network dimension that applies to social interactions is ga:socialInteractionNetwork.
The Social Network dimension that identifies referring social networks is ga:socialNework.
When you filter on Social Network (ga:socialInteractionNetwork), you affect only data in the Social reports that refer to activity around social plugins. You cannot, for example, filter on Social Network to exclude facebook.com.